The Collaborative International Dictionary of English v.0.48:
Abloom \A*bloom"\, adv. [Pref. a- + bloom.] In or into bloom; in a blooming state. --Masson. [1913 Webster]WordNet (r) 3.0 (2006):
abloom adj 1: bursting into flower; "flowering spring trees" [syn: abloom, efflorescent]