trail (v.)youdaoicibaDictYouDict
c. 1300, "to hang down loosely and flow behind" (of a gown, sleeve, etc.), from Old French trailler "to tow; pick up the scent of a quarry," ultimately from Vulgar Latin *tragulare "to drag," from Latin tragula "dragnet, javelin thrown by a strap," probably related to trahere "to pull" (see tract (n.1)). Transitive sense of "to tow or pull along the ground" is from c. 1400. The meaning "follow the trail of" (an animal, etc.) is first recorded late 14c. Meaning "to lag behind" is from 1957. Related: Trailed; trailing.
truth (n.)youdaoicibaDictYouDict
Old English triewð (West Saxon), treowð (Mercian) "faith, faithfulness, fidelity, loyalty; veracity, quality of being true; pledge, covenant," from triewe, treowe "faithful" (see true (adj.)), with Proto-Germanic abstract noun suffix *-itho (see -th (2)).

Sense of "something that is true" is first recorded mid-14c. Meaning "accuracy, correctness" is from 1560s. English and most other IE languages do not have a primary verb for for "speak the truth," as a contrast to lie (v.). Truth squad in U.S. political sense first attested in the 1952 U.S. presidential election campaign.
At midweek the Republican campaign was bolstered by an innovation--the "truth squad" ..., a team of senators who trailed whistle-stopping Harry Truman to field what they denounced as his wild pitches. ["Life," Oct. 13, 1952]


Let [Truth] and Falsehood grapple; who ever knew Truth put to the worse, in a free and open encounter. [Milton, "Areopagitica," 1644]