true (trū)
adj., tru·er, tru·est.

1. 1. Consistent with fact or reality; not false or erroneous. See synonyms at real¹. See Usage Note at fact.
   2. Truthful.
2. Real; genuine. See synonyms at authentic.
3. Reliable; accurate: a true prophecy.
4. Faithful, as to a friend, vow, or cause; loyal. See synonyms at faithful.
5. Sincerely felt or expressed; unfeigned: true grief.
6. Fundamental; essential: his true motive.
7. Rightful; legitimate: the true heir.
8. Exactly conforming to a rule, standard, or pattern: trying to sing true B.
9. Accurately shaped or fitted: a true wheel.
10. Accurately placed, delivered, or thrown.
11. Quick and exact in sensing and responding.
12. Determined with reference to the earth's axis, not the magnetic poles: true north.
13. Conforming to the definitive criteria of a natural group; typical: The horseshoe crab is not a true crab.
14. Narrowly particularized; highly specific: spoke of probity in the truest sense of the word.
15. Computer Science. Indicating one of two possible values taken by a variable in Boolean logic or a binary device.

adv.

1. In accord with reality, fact, or truthfulness.
2. Unswervingly; exactly: The archer aimed true.
3. So as to conform to a type, standard, or pattern.

tr.v., trued, tru·ing, or true·ing, trues.
To position (something) so as to make it balanced, level, or square: trued up the long planks.

n.

1. Truth or reality. Used with the.
2. Proper alignment or adjustment: out of true.

[Middle English trewe, from Old English trēowe, firm, trustworthy.]

trueness true'ness n.

WORD HISTORY   The words true and tree are joined at the root, etymologically speaking. In Old English, the words looked and sounded much more alike than they do now: "tree" was trēow and "true" was trēowe. The first of these comes from the Germanic noun *trewam; the second, from the adjective *treuwaz. Both these Germanic words ultimately go back to an Indo-European root *deru- or *dreu-, appearing in derivatives referring to wood and, by extension, firmness. Truth may be thought of as something firm; so too can certain bonds between people, like trust, another derivative of the same root. A slightly different form of the root, *dru-, appears in the word druid, a type of ancient Celtic priest; his name is etymologically *dru-wid-, or "strong seer."

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The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.

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