It is amazing that the word “trust” has a long and reasonably steady etymology. Its earliest use was in c1200 meaning help, confidence, protection and support; from Old Norse “Traust” “reliance on the veracity, integrity, or other virtues of someone or something.” “Traust” itself has roots for example from Proto-Germanic abstract noun traustam (source also of Old Frisian trast, Dutch troost “comfort, consolation,” Old High German trost “trust, fidelity,” German Trost “comfort, consolation,” Gothic trausti “agreement, alliance”), from Proto-Germanic *treuwaz, source of Old English treowian “to believe, trust,” and treowe“faithful, trusty,” from PIE* root deru- “be firm, solid, steadfast.” Many of these even sounded similar as the modern word.
From c. 1300 as “reliability, trustworthiness; trustiness, fidelity, faithfulness;” from late 14c. as “confident expectation” and “that on which one relies.” From early 15c. in legal sense of “confidence placed in a one who holds or enjoys the use of property entrusted to him by its legal owner.” In the mid-15c. as “condition of being legally entrusted.” Meaning “businesses organized to reduce competition” is recorded from 1877. Is this starting to sound familiar to you Trust Companies?
Trust-buster is recorded from 1903.
c. 1200, from Old Norse treysta “to trust, rely on, make strong and safe,” from traust (see above).
Always nice to get a little education.