trust has 15 distinct synonyms spread across 8 of its 12 senses. Each sense below keeps its own list, because a synonym belongs to a meaning and not to a word: swapping one sense's substitute into another sense's sentence is how a thesaurus makes writing worse. Its 2 recorded opposites are distrust, mistrust.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
something (as property) held by one party (the trustee) for the benefit of another (the beneficiary)
“he is the beneficiary of a generous trust set up by his father”
the trait of believing in the honesty and reliability of others
“the experience destroyed his trust and personal dignity”
a consortium of independent organizations formed to limit competition by controlling the production and distribution of a product or service
“they set up the trust in the hope of gaining a monopoly”
Synonyms, antonyms and the broader and narrower relations for trust come from Princeton University’s WordNet. Full sources and licences.
(chiefly archaic) extend credit to
“don't trust my ex-wife; I won't pay her debts anymore”