The Collaborative International Dictionary of English v.0.48:
Unassuming \Un`as*sum"ing\, a. Not assuming; not bold or forward; not arrogant or presuming; humble; modest; retiring; as, an unassuming youth; unassuming manners. [1913 Webster]WordNet (r) 3.0 (2006):
unassuming adj 1: not arrogant or presuming; "unassuming to a fault, skeptical about the value of his work"; "a shy retiring girl" [syn: retiring, unassuming]