karabiner vs fastening

karabiner and fastening both are nouns.

Word	Noun	Adjective	Verb	Adverb
karabiner	Yes	No	No	No
fastening	Yes	No	No	No

As nouns, fastening is a hypernym of karabiner; that is, fastening is a word with a broader meaning than karabiner:

karabiner: an oblong metal ring with a spring clip; used in mountaineering to attach a rope to a piton or to connect two ropes
fastening: restraint that attaches to something or holds something in place

Other hypernyms of karabiner include fastener, fixing, holdfast, hoop, ring, climbing equipment, rock-climbing equipment.

karabiner (noun)	fastening (noun)
an oblong metal ring with a spring clip; used in mountaineering to attach a rope to a piton or to connect two ropes	the act of fastening things together
	restraint that attaches to something or holds something in place