Where does “քամակ” come from?

քամակ (Armenian) comes from Old Armenian քամակ, from Old Armenian -ակ, from Old Armenian ունակ, from Old Armenian ունիմ, from Proto-Indo-European ōpn-, from Proto-Indo-European ōp- — to achieve.

քամակ (Armenian): back; the posterior part; butt, ass

Definitions

back; the posterior part; butt, ass

Ancestry of “քամակ”, step by step

Step	Language	Word	Meaning
1	Old Armenian	քամակ	back; backbone, spine
2	Old Armenian	-ակ	forming diminutives from nominal stems; forming...
3	Old Armenian	ունակ	having, containing
4	Old Armenian	ունիմ	to have; to take, to hold, to possess, to occupy,...
5	Proto-Indo-European	ōpn-	—
6	Proto-Indo-European	ōp-	to achieve

Every word from Proto-Indo-European ōp- →Every word from Old Armenian -ակ →Every word from Proto-Indo-European ōpn- →