Source : Webster's Revised Unabridged Dictionary (1913)

Slightly \Slight"ly\, adv.
   1. In a slight manner.

   2. Slightingly; negligently. [Obs.] --Shak.

Source : WordNet®

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: {somewhat}]
     2: in a slim or slender manner; "a slenderly built woman";
        "slightly built" [syn: {slenderly}, {slimly}]