/ Dictionary / Index T tool subject: Meaning and Definition of Find definitions for: tool' sub"ject Pronunciation: [key] — Educ. Educ. a subject that, when mastered, equips students with a skill useful in studying other subjects: Grammar is a tool subject for English composition. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. tool steel toom Related Content Daily Word Quiz: cosmology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language