The Collaborative International Dictionary
Thilk
Thilk \Thilk\, pron. [Cf. Ilk same.]
That same; this; that. [Obs.] ``I love thilk lass.''
--Spenser.
Thou spake right now of thilke traitor death.
--Chaucer.
Douglas Harper's Etymology Dictionary
Wiktionary
thilk
det. (context now archaic regional English) That same; this; that. (from 13th c.)