tense up
v 1: become tense, nervous, or uneasy; "He tensed up when he saw
his opponent enter the room" [syn: {tense}, {tense up}]
[ant: {decompress}, {loosen up}, {relax}, {slow down},
{unbend}, {unwind}]
2: cause to be tense and uneasy or nervous or anxious; "he got a
phone call from his lawyer that tensed him up" [syn: {tense},
{strain}, {tense up}] [ant: {loosen up}, {make relaxed},
{relax}, {unlax}, {unstrain}, {unwind}]