The Collaborative International Dictionary of English v.0.48:
Subserviently \Sub*serv"i*ent*ly\, adv. In a subservient manner. [1913 Webster]WordNet (r) 3.0 (2006):
subserviently adv 1: in an obsequious manner; "she acts obsequiously toward her boss" [syn: obsequiously, subserviently, servilely]