cause to be tense and uneasy or nervous or anxious he got a phone call from his lawyer that tensed him up become tense, nervous, or uneasy He tensed up when he saw his opponent enter the room increase the tension on alternately relax and tense your calf muscle tense the rope manually before tensing the spring become stretched or tense or taut the bodybuilder's neck muscles tensed the rope strained when the weight was attached taut or rigid; stretched tight tense piano strings pronounced with relatively tense tongue muscles (e.g., the vowel sound in ‘beat’) in or of a state of physical or nervous tension a grammatical category of verbs used to express distinctions of time