Probably from nagan; a bowl (as pounded out hollow) -- basin, cup, goblet.
see HEBREW nagan
H101. aggan
[אַגָּן] noun [masculine] bowl, basin (Talmud אוֺגָן, Aramaic אַגָּנָא, ; Arabic , vessel in which clothes are washed; Assyrian (plural) aganât¢ DlW).
1 basins used in ritual אֲגָנֹת Exodus 24:6 (E).
2 הַסַּהַר אַגַּן, simile of curves of body Cant 7:3.
3 metaphor of family of Eliakim. הָאַגָּנוֺת כְּלֵי = basin-vessels Isaiah 22:24 (= bowl-shaped vessels Che) opposed to הַנְּכָלִים כְּלֵי; both "" הַקָּטָן כְּלֵי.
אגף (Assyrian stem of agappu, wing, compare DlW).