The Collaborative International Dictionary
Theave
Theave \Theave\, n. [Cf. W. dafad a sheep, ewe.]
A ewe lamb of the first year; also, a sheep three years old.
[Written also thave.] [Prov. Eng.]
--Halliwell.
Wiktionary
theave
n. 1 (context UK dialect English) A ewe lamb of the first year. 2 (context UK dialect English) A sheep three years old.