(1) A sum of money or property held and administered by trustees on behalf of a third party. Under UK/US law, both the trustees and the beneficiaries are regarded as being the owners of the assets or property.

(2) A group with a dominant market position. 'Trust' is seldom used in this sense these days, with the exception of phrases such as 'anti-trust legislation'.

(3) Previously common short form for unit trust (= investment fund).