betrim UK /bɪˈtɹɪm/US /bəˈtɹɪm/ verb1 •(old-fashioned) To trim (“decorate”); to adorn, deck, or embellish.Thy bankes with pioned, and twilled brims / Which spungie Aprill, at thy hest betrims; / To make cold Nymphes chast crownes; […] — 1610 formsbetrimmed · betrimming · betrims