Easily understandable and up-to-date definitions of more than twenty-five thousand terms used in all branches of modern science and technology.

The Basic Dictionary of Science reveals the language of science to the general reader and student, explaining the most recent terms and phrases with precise definitions and exceptional clarity. The words defined are taken from all branches of science, including biology, chemistry, physics, geology, medicine, psychology, astronomy, and anthropology. There are words selected from important technical fields such as engineering, aeronautics, and metallurgy, as well as a smaller group of words to special to science, but nevertheless essential to its structure.

The particular advantage of this up-to-date dictionary is that it is remarkably easy to use because every definition of the 25,000 words and word groups has been written in the 850 words of the Basic English word list, which represents the key ideas we express with our language. Thorough, practical, and simple, this unique dictionary includes 20 pages of reference aids such as periodic tables, conversion factors, and measurable guides.

Dr. E. C. Graham has worked with a group of other scholars and with the Basic English Foundation and the Orthological Institute in preparing this volume over the past fifteen years.

About this book

The special purpose of this Dictionary is to be of help to those interested in science.

In order to make the senses of the words as clear and simple as possible they have been given in Basic English.1 This is not to say that the language of the Dictionary will seem at all unnatural. In fact, without reading this statement, most users would be quite unconscious that it was in any way different from full English. The structure of Basic is quite regular, and the Basic words, though limited in number and controlled in sense, are a selection well representative of the word-store of any person of education. The point in using Basic here is that it makes it necessary to get down to the root ideas at the back of any word before attempting to put it into other words -- a process the outcome of which, though of special help to persons who have had no or little training in science, is without question of value to anybody, even to science experts themselves.

The Dictionary gives the senses of more than 25,000 words and word-groups taken from all branches of Physics, Chemistry, Biology, Medicine, Psychology, Astronomy, Geology, and Anthropology, as well as from important fields of science in industry, such as Engineering, Aeronautics, and Metallurgy.2 In addition, a small number of words have been put in which are not special to science, but which are so much a part of its framework that science reading is unable to get far without a knowledge of them.

The general level of selection and detail is about that of a first-year university work. Though in the present condition of growth in science, when new discoveries are being made, and new words and senses are coming into the language, at an unparalleled rate, it is impossible for any dictionary to be completely up to the minute, every care has been taken to get in all the important new words which have become current up to the time of printing.

The system of the Dictionary is very simple, and the rules and directions given on pp. ix to xvi will make it all quite clear without further observations. There is, however, one point on which it may be well to say something.

Naturally, any science word in the Dictionary may be used in giving the sense of another; but when a word so used is not Basic, it is put in special print. What is to be noted is that no attempt has been made to do without this use of science words needing to be looked up, or to put any unnatural limit to the number which may be used in any one connection. From this point of view, a science dictionary is quite different from a general dictionary. Every science not only has its key-words, which come into almost everything general which has to be said about it, and in relation to which other words have to be placed, but it has groups of words having such a connection with one another that a knowledge of one is incomplete without a knowledge of the others. It is the business of a dictionary of this sort not only to give the senses of words but to give them in such a way that the reader sees these words in the complex of which they are a part.

The Dictionary was first undertaken a part of the programme made possible by the support given by the Rockefeller foundation to the Orthological Institute before the war. The earliest form of it was produced in 1938-9 by Dr. H. Stanfford Hatfield. Though in the end, when ideas as to the range and level and organization of the Dictionary had become clearer, very little of this first attempt was used, it was of value in getting together a mass of material and in pointing by example to the dangers to be kept clear of and the questions needing decision; and in that sense the present Dictionary may be said to be based on it.

Nothing more was done while the war was on and for some time after, but in 1947 the work was started again with money from the newly-formed Basic English Foundation, and by 1949, after much discussion with men of science in all fields, and the special help of Dr. James Lawrie,3 who went through the material in detail, the lines on which the book was to be worked out ha been more or less fixed. I then became responsible for the detailed organization and for the Basic side of the work, with Mr. William Grubb as my chief helper at the Orthological Institute and Mr. C. L. Boltz (at that time Science Correspondent at the B.B.C.) to oversee the science side. Among the great number of other experts who gave their help at the different stages on general or special questions, or in special fields, were, most importantly: Dr. J. A. Lauwerys, Professor of Comparative Education in the University of London and Chairman of the Basic English Foundation; Dr. G. C. Ainsworth of the commonwealth Mycological Institute at Kew; and the late Dr. G. A. Thomas of Guy's Hospital Medical School.

In 1953 the work was complete, but first the ending of Government support and then the death of C. K. Ogden kept it from getting into print. It was not till 1960 that it was taken up again, and we were then faced by the need for the addition of he great number of new words which had become current in the years between, and for other changes made necessary by the unparalleled expansion of science in those years. In making these additions and changes, I had the help of Mr. Norman Manners, whose work keeps him in touch with new developments in science on a very wide front and whose experience and knowledge were of the very greatest value.4 I am happy to give credit here to all those who had a hand in getting the Dictionary into its present form, and specially to put on record my great debt to Mr. Bolz and Mr. Manners for the care and interest they took in clearing up complex points so that they might be put in simple English.

This account is itself all in Basic English.


  1. The word-list of Basic English is a selection of 850 English words chiefly representative of those key ideas into which more complex ones may be broken down, and it is used with the addition of such words as are common to all the important languages at the present-day -- among them a number of science words and the names of the chief sciences themselves.
  2. A more detailed view of the fields covered may be got from the list of Science Guides on p. xiii.
  3. Then Editor of Chemical Products and The Chemical News.
  4. Mr. Manners was at that time Chief Press Officer for the Department of Scientific and Industrial Research.

Simplish contains this dictionary, expanded and updated.