Source : Webster's Revised Unabridged Dictionary (1913)

Wriggle \Wrig"gle\, v. i. [imp. & p. p. {Wriggled}; p. pr. & vb.
   n. {Wriggling}.] [Freq. of wrig, probably from OE. wrikken to
   move to and fro; cf. LG. wriggeln, D. wrikken, Sw. vricka,
   Dan. vrikke.]
   To move the body to and fro with short, writhing motions,
   like a worm; to squirm; to twist uneasily or quickly about.

         Both he and successors would often wriggle in their
         seats, as long as the cushion lasted.    --Swift.