intransitive verb effloresced -·resced′, efflorescing -·resc′·ing

1. to blossom out; flower; bloom
2. Chem.
   1. to change from a crystalline to a powdery state through loss of the water of crystallization when exposed to air
   2. to develop a powdery crust as a result of evaporation or chemical change

Etymology: L efflorescere, to blossom, flourish < ex-, out + florescere, to begin to blossom < florere, to blossom < flos (gen. floris), a flower: see bloom