effloresce

Concise Oxford English Dictionary © 2008 Oxford University Press:
effloresce /ˌɛfləˈrɛs/

▶verb

• 1 (of a substance) lose moisture and turn to a fine powder on exposure to air.

• 2 (of salts) come to the surface of brickwork or other material and crystallize.

  ■ (of a surface) become covered with salt particles.

• 3 reach an optimum stage of development.

– derivatives
efflorescence noun,
efflorescent adjective.

– origin C18: from L. efflorescere, from e- (var. of ex-) ‘out’ + florescere ‘begin to bloom’.