यत्

Sanskrit

From Proto-Indo-Iranian *yat- (“to reach, take position”), from Proto-Indo-European *yet- (“to bring, conform, support”); cognate with Persian (faryâd, “cry, shout”), Latin nītor (“support oneself, brace oneself”), Tocharian A yät- (“to adorn”), Ancient Greek ὅσιος (hósios, “just, fair”).

यत् • (yat)

to place in order, marshal, join, connect
to keep pace, be in line, rival or vie with
to join, associate with, march or fly together or in line
to conform or comply with
to meet, encounter (in battle)
to seek to join one's self with, make for, tend towards
to endeavour to reach, strive after, be eager or anxious for
to exert one's self, take pains, endeavour, make effort, persevere, be cautious or watchful
to be prepared for
to join, unite, attach to
to cause to fight
to strive to obtain anything
to requite, return, reward or punish, reprove
to surrender or yield up anything to
to distress, torture, vex, annoy

Monier Williams (1899) “यत्”, in A Sanskrit–English Dictionary, […], new edition, Oxford: At the Clarendon Press, →OCLC, page 840/3.
William Dwight Whitney, 1885, The Roots, Verb-forms, and Primary Derivatives of the Sanskrit Language, Leipzig: Breitkopf and Härtel, page 129
Mayrhofer, Manfred (1996) Etymologisches Wörterbuch des Altindoarischen [Etymological Dictionary of Old Indo-Aryan]‎^[1] (in German), volume 2, Heidelberg: Carl Winter Universitätsverlag, pages 394-5
Lubotsky, Alexander (2011) The Indo-Aryan Inherited Lexicon (in progress) (Indo-European Etymological Dictionary Project), Leiden University, pages 612-3
Cheung, Johnny (2007) Etymological Dictionary of the Iranian Verb (Leiden Indo-European Etymological Dictionary Series; 2), Leiden, Boston: Brill, →ISBN, page 215