- Thine is defined as something belongs to you.
An example of thine is John telling Mary that the horse belongs to John, by saying the horse is thine.
Origin: Middle English thin from OE, genitive of thu, thou ( Middle English loss of -n before a consonant gives thy)
Used by arrangement with John Wiley & Sons, Inc.
pron. (used with a sing. or pl. verb)
Origin: Middle English thin; see thy.