PTMeg 70.b:25[2] :צומא רבא בערובתא‏ : the Day of Atonement is on Friday
See the entire entry for ˁrūḇā, ˁrūḇtā n.f. eve

PTMeg 70.b:25[2] :צומא רבא‏ : the great fast (i.e., Yom Ha-Kippurim)
See the entire entry for ṣō/awm, ṣō/awmā n.m. fast