seizing vs clench

seizing and clench both are nouns.

Word	Noun	Adjective	Verb	Adverb
seizing	Yes	No	No	No
clench	Yes	No	Yes	No

As nouns, clench is a hyponym of seizing; that is, clench is a word with a more specific, narrower meaning than seizing:

seizing: the act of gripping something firmly with the hands (or the tentacles)
clench: the act of grasping

Other hyponyms of seizing include clasp, clutch, clutches, grasp, grip, hold.

seizing (noun)	clench (noun)
the act of gripping something firmly with the hands (or the tentacles)	the act of grasping
small stuff that is used for lashing two or more ropes together	a small slip noose made with seizing

seizing (verb)	clench (verb)
	hold in a tight grasp
	squeeze together tightly