Them

From Middle English, form Old Norse.

Full definition of them

(personal pronoun, objective case)

Third personal plural pronoun used after a preposition or as the object of a verb.Give it to them. (after preposition)She wrote them a letter. (indirect object)She treated them for a cold. (direct object)
Third-person singular pronoun of unspecified (indeterminate or irrelevant) gender.If someone comes and asks for the ticket, just give it to them. (after preposition)If one of my patients calls, please bring them their dinner. (indirect object)If a student has an inappropriate question, whatever you do, do not berate them. (direct object)

1611, King James Bible, :If there be found among you, within any of thy gates which the LORD thy God giveth thee, man or woman, that hath wrought wickedness in the sight of the LORD thy God, ... then shalt thou bring forth that man or that woman, which have committed that wicked thing, unto thy gates, even that man or that woman, and shalt stone them with stones, till they die.
2006, St. John Ambulance, First on the Scence: Student Reference Guide, Place the casualty on their back with feet and legs raisedâ€”this is called the shock position. in original Once the casualty is positioned, cover them to preserve body heat, but do not overheat.

For notes on the usage referring to a person of unspecified gender, see the usage notes for they.