crab vs quetch

crab is a noun but quetch is not a noun.

Word	Noun	Adjective	Verb	Adverb
crab	Yes	No	Yes	No
quetch	No	No	Yes	No

As verbs, quetch is a hypernym of crab; that is, quetch is a word with a broader meaning than crab:

Other hypernyms of crab include complain, kick, kvetch, plain, sound off.

crab (noun)	quetch (noun)
a stroke of the oar that either misses the water or digs too deeply
decapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers
a louse that infests the pubic region of the human body
the edible flesh of any of various crabs
a quarrelsome grouch

crab (verb)	quetch (verb)
complain	express complaints, discontent, displeasure, or unhappiness
fish for crab
scurry sideways like a crab
direct (an aircraft) into a crosswind