固くなる

(1)increase the tension on; "alternately relax and tense your calf muscle"; "tense the rope manually before tensing the spring"

(2)緊張を高める

(3)become stiff or stiffer; "He stiffened when he saw his boss enter the room"

(4)堅く、またはより堅くなる

(5)cause to be tense and uneasy or nervous or anxious; "he got a phone call from his lawyer that tensed him up"

(6)緊張や心配あるいは神経質であるか気がかりを引き起こす

(7)become tense, nervous, or uneasy; "He tensed up when he saw his opponent enter the room"

(8)緊張しているか、神経質か、不安になる

(1)