their

• thair, theire, theyr, theyre, thir (archaic)

From Old Norse þeirra. Replaced native Old English heora.

• (UK) IPA^(key): /ðɛə(ɹ)/, /ðɛː(ɹ)/

• Audio (UK):

  (file)

• (US) IPA^(key): /ðɛɚ/
  • (unstressed form) IPA^(key): /ðɚ/

• Audio (US, stressed form); /ðɛɚ/:

  (file)

• (Canada) IPA^(key): [ðeːɹ]
• Homophones: there, they're
• Rhymes: -ɛə(ɹ)

their

1. Belonging to, from, of, or relating to, them (plural).

   they will meet tomorrow at their convenience

   this is probably their cat

   • 1831, Thomas Carlyle, “Symbols”, in Sartor Resartus: The Life and Opinions of Herr Teufelsdröckh. […], London: Chapman and Hall, […], →OCLC, 3rd book, page 155:

     For all things, even Celestial Luminaries, much more atmospheric meteors, have their rise, their culmination, their decline.

   • 2012 May 5, Phil McNulty, “Chelsea 2-1 Liverpool”, in BBC Sport:

     For Liverpool, their season will now be regarded as a relative disappointment after failure to add the FA Cup to the Carling Cup and not mounting a challenge to reach the Champions League places.

   • 2013 July 20, “The attack of the MOOCs”, in The Economist, volume 408, number 8845:

     Since the launch early last year of […] two Silicon Valley start-ups offering free education through MOOCs, massive open online courses, the ivory towers of academia have been shaken to their foundations. University brands built in some cases over centuries have been forced to contemplate the possibility that information technology will rapidly make their existing business model obsolete.

2. Belonging to someone (one person, singular), or occasionally to something.
   • c. 1594 (date written), William Shakespeare, “The Comedie of Errors”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene iii], line 1172:

     There's not a man I meet but doth salute me
     As if I were their well-acquainted friend […]

   • 2006, St. John Ambulance, First on the Scene: Student Reference Guide, →ISBN, Lesson 2, page 3:

     Place the casualty on their back with feet and legs raised—this is called the shock position. [emphasis in original] Once the casualty is positioned, cover them to preserve body heat, but do not overheat.

   • 1980, Bill Oddie, Bill Oddie's Little Black Bird Book, page 112:

     I prefer to think that birds have a sufficiently developed sense of humour to enjoy the spectacle of a human being hunched beneath a bush kissing the back of their hand.

   • 2007, J. K. Rowling, Harry Potter and the Deathly Hallows, (quoted edition: London: Bloomsbury, 2008, →ISBN, page 93):

     ‘I mean ... if somebody made a mistake,’ Harry went on, ‘and let something slip, I know they didn’t mean to do it. It’s not their fault,’ he repeated, again a little louder than he would usually have spoken.

   • 2021, Stern, Moore, Grundy, Young & Binzel, editor, The Pluto System after New Horizons, page 38:

     The only object ... showing the signature of N₂ in their spectra is Sedna.

   • For more quotations using this term, see Citations:their.

• Regarding the use of singular their, see they.
• The words their, there, and they're are homophones in most English accents today. This often causes confusion between the three in writing.

• they, them (personal pronouns, subject and object case)
• theirs (possessive pronoun)

their

1. Misspelling of there.

their

1. Misspelling of they’re.

• Erith, Reith, Rieth, Thier, rithe, tehri, theri-

their

1. Alternative form of þeir

• IPA^(key): /heɾʲ/
• (Uist) IPA^(key): [veɾʲ]

their

1. future of abair

• The dependent form is abair.
• Canaidh is more frequently used by most speakers nowadays.