c. 1200, "reliance on the veracity, integrity, or other virtues of someone or something; religious faith," from Old Norse traust "help, confidence, protection, support," 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."

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;" mid-15c. as "condition of being legally entrusted." Meaning "businesses organized to reduce competition" is recorded from 1877. Trust-buster is recorded from 1903.

c. 1200, from Old Norse treysta "to trust, rely on, make strong and safe," from traust (see trust (n.)). Related: Trusted; trusting.

also antitrust, "opposed to the political power or influence of organized business interests," 1890, U.S., from anti- "against" + trust (n.) in the "economic monopoly" sense.

"group of experts assembled to give advice on some matter," occasionally used since early 1900s, it became current in 1933, in reference to the intellectuals gathered by the administration of incoming U.S. President Franklin D. Roosevelt as advisers; from brain (n.) + trust (n.).

1540s, "small ball used in voting," also "secret vote taken by ballots," from Italian pallotte, diminutive of palla "ball," for small balls used as counters in secret voting, from a Germanic source (from PIE root *bhel- (2) "to blow, swell"). The earliest references are to Venice. By 1776 the sense of the word had been extended to tickets or sheets of paper used in secret voting. Ballot box attested from 1670s; metonymically from 1834 as "system or practice of voting by ballot."

1570s, "assumed as a fixed basis for comparison," from Latin fiducialis "reliable," from fiducia "trust" (from PIE root *bheidh- "to trust, confide, persuade"). From 1620s as "pertaining to trust;" 1832 as "fiduciary."

1640s, "holding something in trust," from Latin fiduciarius "entrusted, held in trust," from fiducia "trust, confidence, reliance;" in law, "a deposit, pledge, security," from root of fidere "to trust" (from PIE root *bheidh- "to trust, confide, persuade"). In Roman law, fiducia was "a right transferred in trust;" paper currency sense (1878) is because its value depends on the trust of the public. As a noun, "one who holds something in trust," from 1630s.

1520s, "to promise," from Old French afiancier "to pledge, promise, give one's word," from afiance (n.) "confidence, trust," from afier "to trust," from Late Latin affidare, from ad "to" (see ad-) + fidare "to trust," from fidus "faithful" (from PIE root *bheidh- "to trust, confide, persuade").

From mid-16c. especially "to promise in marriage." The earlier form of the word was affy (Middle English affien "to trust, have faith; have faith in" c. 1300), from Old French afier. Related: Affianced; affiancing.

1822, "advocate of extension of the political franchise in Britain," without regard to gender, or, in the U.S., of voting rights for free blacks; from suffrage + -ist. After c. 1885 especially with reference to voting rights for women.

mid-15c., "to place trust or have faith," from Latin confidere "to trust in, rely firmly upon, believe," from assimilated form of com, here perhaps an intensive prefix (see com-), + fidere "to trust" (from PIE root *bheidh- "to trust, confide, persuade"). Meaning "to share a secret with, take into one's confidence" is from 1735; phrase confide in (someone) is from 1888. Related: Confided; confiding.