Thier

Part of speech: determiner, pronoun

Definitions

1. A frequent misspelling of the possessive word meaning belonging to or associated with them
2. An incorrect spelling of the word that shows something is owned by or connected to a group of people or things
3. A mistaken way of writing the possessive form used for something that belongs to them

Etymology: The word is a misspelling of "their," so the real story belongs to "their" itself. Its ancestry runs back to Proto-Germanic "*þaizǭ," which passed into Old Norse as "þeira" and "þeirra," forms that were used alongside a native English pronoun. That native pronoun was the Old English "heora," which was eventually displaced by the Norse form. This is one of the more striking examples of Norse influence on English. The Vikings settled large parts of northern and eastern England, and their speech mixed with the local Old English. The new pronoun was adopted into English, and the old native word lost out. Ordinary words such as "they" and "them" came into English in the same period, from the same Scandinavian source, which is why these pronouns look so different from the older forms they replaced.