logarithmic: of a logarithm, a figure that tells to what power a certain fixed number, as ten, must be raised to equal a given number. For example, the logarithm of 100 is 2, when 10 is taken as the fixed number (102 = 100). Such numbers are listed in tables to shorten the working of problems in mathematics. Tetrahedral: of a tetrahedron, a solid object with four sides; a pyramid with three sides and a triangular base. The phrase logarithmic tetrahedral has no sensible meaning and is used humorously in the lecture to indicate very educated sounding nonsense. —Editor, from Webster's Dictionary for Young Readers and OxfordAmericanDictionary (5th ACC Glossary Part 1) Final approval 2.12.89