אָפֶס 'apes used either of the "end" of something in the phrase "the ends of the earth" or to express its absence: "no one, nothing etc." as in Am 6:10.

In Am 9:8 (as in Num 13:28; Dt 15:4; Jdg 4:9; 2 Sam 12:14) the phrase אֶפֶס כִּי expresses a contrast and means "yet, however, nevertheless".