The Smarandache's Synonymity Test:
similar to, and an extension of, the antonym test in psychology,
is a verbal test where the subject must supply as many as possible synonyms
of a given word within a as short as possible period of time.
How to measure it?
The spectrum of supplied synonyms (s), within the measured period of time (t),
shows the subject's level of linguistic neutrosophy: s/t.

George Hammond mentioned that "this test is more related to Intelligence than to
Personality" and "besides having a high loading on IQ (or psychometric-g) it might
also have a number of specific factors, such as Reading Level, in a factor analysis
procedure".  "(...) if you gave such a test to a group of subjects, and also included
tests for Intelligence, Personality, Reading Ability, etc. and then factored the
resulting correlation matrix, I think you would find the highest loading on Reading
Level, then IQ, then Personality".