fidget

Short definition from Wiktionary

Verb

1. 1
   To wiggle or twitch; to move the body, especially the fingers, around nervously or idly.
2. 2
   To cause to fidget; to make uneasy.

Noun

1. 1
   A nervous wriggling or twitching motion.
2. 2
   A person who fidgets, especially habitually.
3. 3
   An object intended to be fidgeted with (such as a tool or toy).