[ef.flo.resce] vi -resced ; -resc.ing [L efflorescere, fr. ex- + florescere to begin to blossom--more at florescence] (1775) 1: to burst forth: bloom
2. a: to change to a powder from loss of water of crystallization b: to form or become covered with a powdery crust "bricks may ~ owing to the deposition of soluble salts"