Green’s Dictionary of Slang

lig n.2

also liggety
[Scot. lug, a fool]

(Ulster) a fool (lig is male, liggety female).

[US]J. O’Connor Come Day – Go Day (1984) 10: God knows where those two ligs have got to this time.
[Ire]MacAfee Concise Ulster Dict. 206/1: liggety, ligoty [...] 1. a tall, useless fellow. 2. an excitable, foolish person.