What is the meaning of þeir?

: nominative plural of the word hann meaning "he"; literally meaning "they"

:, plural of

Third-person plural genitive determiner: their

Third-person plural possessive pronoun: theirs, of them

Brink, Daniel (1992) “Variation between <þ-> and <t-> in the Ormulum”, in Irmengard Rauch, Gerald F. Carr and Robert L. Kyes, editors, On Germanic Linguistics: Issues and Methods (Trends in Linguistics. Studies and Monographs; 68), De Gruyter Mouton, →DOI, →ISBN, pages 21-35.

Thurber, Beverly A. (2011 February 15) “Voicing of Initial Interdental Fricatives in Early Middle English Function Words”, in Journal of Germanic Linguistics, volume 23, number 1, Cambridge University Press, →DOI, pages 65-81.

their(e,, pron.”, in MED Online, Ann Arbor, Mich.: University of Michigan, 2007, retrieved 4 June 2018.

those

they

Source: wiktionary.org