PC

*ˀaps- - extremity (HALOT 79, DRS 29, Kogan 2015: 283)

as suggested by HALOT 79 and DRS 29, may be borrowed from Akk. apsû ‘cosmic subterranean water’, in its turn going back to Sum. abzu.

Ugaritic
ˀaps - extremity, edge, end (DUL 91)
Amarna Canaanite
up-sí-ḫi - extremity (DNWSI 97)
In EA 366:34, as a gloss to ZAG!.ḪI<.A>-ši (Rainey 1978:34‒35, 98). For a different evaluation v. van Soldt 1997, who prefers to relate up-sí- to Ugr. ˁbs/ˁps ‘landmark, boundary’ (DUL 174)
Phoenician
ˀps - only (DNWSI 97)
Hebrew
ˀäpäs - extremity, end; end, nothing, nothingness; notwithstanding (HALOT 79)
Hebrew
ˀps - to be at an end, to be no more (HALOT 79)
Hebrew
ˀopsayim - the two extremities (HALOT 79)