"looking well, aesthetically befitting," 1560s, from earlier sense of "fitting, proper" (early 13c.), present-participle adjective from become. Related: Becomingly; becomingness.
her becoming modesty
a becoming new shade of rose
a becoming portrait
beche-de-mer
beck
beckon
becloud
become
becoming
bed
bedaub
bedazzle
bed-board
bedbug