clench / klench/ • v. (with reference to the fingers or hand) close into a tight ball, esp. when feeling extreme anger: [tr.] she clenched her fists, struggling for control | [intr.] John's right hand clenched into a fist. ∎  (with reference to the teeth) press or be pressed tightly together, esp. with anger or determination or so as to suppress a strong emotion: [intr.] her teeth clenched in anger. ∎  [tr.] grasp (something) tightly, esp. with the hands or between the teeth. ∎  [intr.] (of a muscular part of the body) tighten or contract sharply, esp. with strong emotion.• n. [in sing.] a contraction or tightening of part of the body: she saw the anger rise, saw the clench of his fists. ∎  the state of being tightly closed or contracted.

clench fix or grasp firmly XIII; close tightly (the fist, etc.) XVIII. OE. -clenċan = OHG. klenken :- Gmc. *klaŋkjan, f. *klaŋk- *kleŋk- *kluŋk-, parallel to *klaŋg-, etc. (see CLING). Cf. CLINCH.