Blossom (noun, verb) noun (C, U) a flower or a mass of flowers, especially on a fruit tree or bush: cherry / orange / apple blossom. The trees are in blossom. Visual vocab page V8 verb. 1) I (of a tree or bush) to produce blossom. 2) I to become more healthy, confident or successful: she has visibly blossomed over the last few months. Into something their friendship blossomed into love.