Thine
Thine (tīn) , pronoun and adjective
[Old English thin, Anglo-Saxon eīn, originally gen. of eu, eū, thou; akin to German dein thine, Icelandic þinn, possessive pron., þīn, gen. of þū thou, Gothic þeins, possessive pron., þeina, gen. of þu thou. See Thou, and compare Thy.]
A form of the possessive case of the pronoun thou, now superseded in common discourse by your, the possessive of you, but maintaining a place in solemn discourse, in poetry, and in the usual language of the Friends, or Quakers.
In the old style, thine was commonly shortened to thi (thy) when used attributively before words beginning with a consonant; now, thy is used also before vowels. Thine is often used absolutely, the thing possessed being understood.