Definition of "their"

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

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

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.

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

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.

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

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

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, [Act IV, scene iii], line 1172

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.

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

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.

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

‘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.

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

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

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