Definition: nm. & ac. sg. n. and base °ree;-- of the rel. prn. what, which; cj. that (introducing oratio recta, gnly. without iti, after verbs of saying, thinking, etc.); (so) that (rare); as to the fact that (corr. tad, therein); where fore, on which account (rare); when (V.); if (V.; in Br. with pot. to express an unfulfilled condition); since, because, inasmuch as (corr. tad, therefore; common); in order that (rare); ádha yád, even if, although (RV.); yad api, although; yad u -evam, as -so (V.); yad uta, that; that is to say; yat kila, that; yak ka, if that is to say; yad vâ, or else (very common in comm.); however; yad vâ -yadi vâ, if -or if.