Definition of: true

(tr) adjective tru·er, tru·est
1. Faithful to fact or reality; not false or erroneous: a true judgment or proposition.
2. Being real or natural; genuine, not counterfeit: a true specimen, true gold.
3. Faithful to friends, promises, or principles; loyal; steadfast: true love, a true friend.
4. Conformable to an existing standard type or pattern; exact: a true copy.
5. Accurate, as in shape, dimensions, or position: a true fit, a true circle.
6. Faithful to the requirements of law or justice; legitimate: the true king.
7. Faithful to truth; trustful; honest: a true man.
8. Faithful to the promise or predicted event; correctly indicative: a true sign.
9. Biol. a Possessing all the attributes of a developed organ or structure of its class; complete. b Of pure strain or pedigree: a true collie dog. c Conformed to the structure of the type; properly so called: said of a plant or animal, as distinguished from others improperly so called: a true locust.
10. Exactly correspondent in pitch or key; in perfect tune: His voice is true. See synonyms under AUTHENTIC, CORRECT, FAITHFUL, GOOD, HONEST, JUST¹, MORAL, RIGHT, PURE.
—noun
1. Truth; covenant; pledge.
2. plural trues or truce Obs. An armistice or truce.
—in (or out of) true In (or not in) line of adjustment: said of a mark or part, as in a drawing or a machine.
—adverb
1. In truth; truly.
2. In a true and accurate manner: The wheel runs true.
3. Conformably to the ancestral type: in the phrase to breed true.
—v.t. trued, tru·ing To bring to conformity with a standard or requirement; form or adjust, as with geometrical precision: to true a frame or a tool. [OE trēowe. Akin to TRUCE, TRUST.]
—true′ness noun