squiggle

Short definition from Wiktionary

Noun

1. 1
   A short twisting or wiggling line or mark.
2. 2
   Synonym of tilde.
3. 3
   An illegible scrawl.

Verb

1. 1
   To wriggle or squirm.
2. 2
   To make a squiggle.
3. 3
   To write illegibly.