customary UK /ˈkʌs.tə.m(ə.)ɹi/US /ˈkʌs.təˌmɛɹ.i/adjective 2noun 1forms 3 adjective2 •In accordance with, or established by, custom or common usage.When two people met for the first time in Diaspar—or even for the hundredth—it was customary to spend an hour or so in an exchange or courtesies before getting down to business, if any. — 1956 •Holding or held by custom.customary tenants noun1 •A book containing laws and usages, or customs; a custumal. formscustomaries · more customary · most customary