Great Britain, UK, United Kingdom, United Kingdom of Great Britain and Northern Ireland, Britain, GB - a monarchy in northwestern Europe occupying most of the British Isles; divided into England and Scotland and Wales and Northern Ireland

cramp, muscle spasm, spasm - a painful and involuntary muscular contraction

biochemist - someone with special training in biochemistry

tense up, tense, strain - make tense and uneasy or nervous or anxious;