Green’s Dictionary of Slang

twitchety adj.

also twitchetty

[SE twitch]

nervous, fidgety.

1859		Hotten Dict. of Modern Sl. etc. 113: TWITCHETTY, nervous, fidgetty.
1864, 1867, 1870		Hotten Sl. Dict. [as cit. 1859].
1890–1904		Farmer & Henley Sl. and Its Analogues.