The Collaborative International Dictionary of English v.0.48:

Skirmish \Skir"mish\, v. i. [imp. & p. p. Skirmished; p. pr. &
   vb. n. Skirmishing.] [OE. skirmishen, scarmishen, OF.
   escremir, eskermir, to fence, fight, F. escrimer, of German
   origin; cf. OHG. scirmen to protect, defend, G. schirmen,
   OHG. scirm, scerm, protection, shield, G. schirm; perhaps
   akin to Gr. ???? a sunshade. Cf. Scaramouch, Scrimmage.]
   To fight slightly or in small parties; to engage in a
   skirmish or skirmishes; to act as skirmishers.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Skirmish \Skir"mish\, n.[OE. scarmishe, scrymishe. See
   Skirmish, v. i.]
   1. A slight fight in war; a light or desultory combat between
      detachments from armies, or between detached and small
      bodies of troops.
      [1913 Webster]

   2. A slight contest.
      [1913 Webster]

            They never meet but there's a skirmish of wit.
                                                  --Shak.
      [1913 Webster]

WordNet (r) 3.0 (2006):

skirmish
    n 1: a minor short-term fight [syn: brush, clash,
         encounter, skirmish]
    v 1: engage in a skirmish