BT Ber 3b(35) :תרי נשפי הוו נש̇ף <ימ>מ̇א אתא ליליא נשף ליליא אתא יממא‏ : there were two twilights: the daytime blows away and night comes; the night blows away and daytime comes
See the entire entry for nšp vb. to blow

BT Ber 3b(35) :תרי נשפי הוו‏ : there are two twilights
See the entire entry for nšep̄, *nišpā n.m. twilight or dawn