From Longman Dictionary of Contemporary Englishseize up phrasal verb1 STOP MOVINGif an engine or part of a machine seizes up, its moving parts stop working and can no longer move, for example because of lack of oil The mechanism had seized up.2 STOP MOVINGif a part of your body, such as your back, seizes up, you suddenly cannot move it and it is very painful → seize→ See Verb table
