behalf

Etymology

From Middle English bihalve (“nearby”), from Old English bī healfe (“by [his/her] side”), from bī (“by”) + healfe (“side, half”), equivalent to be- + half.

noun

1. The interest, benefit, or wellbeing of someone or something.
   The one exception to this was William Hilhouse, who was widely regarded as the colonist with the greatest experience of the interior and its native inhabitants, on whose behalf he endlessly campaigned. 2006, Peter Rivière, The Guiana Travels of Robert Schomburgk, 1835-1844
   The NUL, on the other hand, never felt that its position among civil rights organizations was threatened, and considered itself unique because of its historic commitment to advocacy on behalf of low-income African Americans. 2013, Catherine M. Paden, Civil Rights Advocacy on Behalf of the Poor, page 108
2. (when adopted by someone else) One's role or rightful place; stead or authority.
   He was not only my Representative who died on my behalf; He was my Substitute who died in my very stead. 1994, J. Sidlow Baxter, Awake, My Heart: Daily Devotional Studies for the Year, page 104
   Which indeed is so true, that she herself may seek back for her own gain the dowry offered by another on her behalf, unless by chance he who offered it immediately (that is, at the time of offering or of promising) stipulated or made an agreement that the afore-mentioned dowry would be returned to him. 2002, Judith Evans Grubbs, Women and the Law in the Roman Empire
   The Agent shall have all of the powers, rights, discretions, elections, and authority conferred by statute, the common law, or rule of court or governmental agency that are reasonably necessary for the Agent to act on my behalf for any purpose. 2004, Joan M. Burda, Estate Planning for Same-sex Couples, page 133