blossom

Concise Oxford English Dictionary © 2008 Oxford University Press:
blossom/ˈblɒsəm/

▶noun a flower or a mass of flowers on a tree or bush.

■ the state or period of flowering.

▶verb

• 1 (of a tree or bush) produce blossom.

• 2 mature or develop in a promising or healthy way.

– derivatives
blossomy adjective.

– origin OE blōstm, blōstma (n.), blōstmian (v.), of Gmc origin; rel. to bloom1.