From WordNet (r) 3.0 (2006) [wn]:
slightly
adv 1: to a small degree or extent; "his arguments were somewhat
self-contradictory"; "the children argued because one
slice of cake was slightly larger than the other" [syn:
slightly, somewhat, more or less]
2: in a slim or slender manner; "a slenderly built woman";
"slightly built" [syn: slenderly, slimly, slightly]
From The Collaborative International Dictionary of English v.0.48 [gcide]:
Slightly \Slight"ly\, adv.
1. In a slight manner.
[1913 Webster]
2. Slightingly; negligently. [Obs.] --Shak.
[1913 Webster]