themself

English edit

From Middle English theimself. Equivalent to them +‎ -self. Reinforced by analogy with the singular-plural distinction between yourself and yourselves.

themself (third person, singular reflexive of they)

(reflexive, sometimes proscribed) The reflexive form of they, the third-person singular personal pronoun. The single person previously mentioned, as the object of a verb or following a preposition (also used for emphasis).
Someone could hurt themself.

Anyone who wants a car like mine can buy one themself.
- 1899 December 6, “Paw Baldness”, in Shiner Gazette:
  […] they woulden't ^[sic] always be trying to make Themself Look Diffarunt ^[sic] from what nature made Them.
- 2009 January 8, Samantha Maiden, “Hoaxer, out yourself: 'Demidenko'”, in The Australian‎^[1]:
  THE author who masqueraded as Helen Demidenko yesterday urged the hoaxer who deceived the respected right-wing journal Quadrant to unmask themself.
- 2013 January 8, John Stoltenberg, Gonerz:
  ... somedays there will be an odd number of quadders and so somebody might have to sit by themself in the back.
(nonstandard, sometimes proscribed) Synonym of themselves (the third-person plural).
- 1822, John Strype, Ecclesiastical Memorials, Relating Chiefly to Religion, page 119:
  […] and the same is here thought of al men to be so vailable and sufficient, as can be required, accept and take the said commission and dispensation so thankfully, and themself so satisfied with the same, that they repute and think themself not only singularly obstringed and bound to the Popes […]

The use of themself instead of themselves is sometimes proscribed,^[1] but it is relatively common "considering that singular they is unquestionably far less frequent than plural they".^[2] Furthermore, the use of themself as a singular and themselves as a plural is in "clear parallel [to] common usage of the second-person forms, where yourselves can be contrasted with yourself",^[3] and the same is true in the first person, where ourselves contrasts with ourself.
For more on the use of they as a singular pronoun, see they.
For information on the use of he and himself as a generic singular pronoun, see he.

^ Carl W. Hart (2012) Rocket English Grammar, →ISBN, page 55: “Many English teachers believe themself is a serious crime against English grammar. They are not happy when people use they, them, or their to talk about only one person, but they really hate it when people use themself.”
^ Geoffrey Sampson, Anna Babarczy (2013) Grammar Without Grammaticality: Growth and Limits of Grammatical Precision, →ISBN, page 56
^ Laura Paterson (2014) British Pronoun Use, Prescription, and Processing, →ISBN, page 170