Wordnet 3.0
NOUN (1)
1. 
 the sound of (the chanter of) a bagpipe; 
VERB (2)
1. 
 make a shrill, wailing sound; 
- Example: "skirling bagpipes"2. 
 play the bagpipes; 
The Collaborative International Dictionary of English v.0.48:
Skirl \Skirl\, v. t. & i. [Of Scand. origin, and originally the
   same word as E. shrill.]
   To utter in a shrill tone; to scream. [Prov. Eng. & Scot.]
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Skirl \Skirl\, n.
   A shrill cry or sound. [Prov. Eng. & Scot.]
   [1913 Webster]
WordNet (r) 3.0 (2006):
skirl
    n 1: the sound of (the chanter of) a bagpipe
    v 1: make a shrill, wailing sound; "skirling bagpipes"
    2: play the bagpipes