| BMU | basic metabolic unit; basic multicellular unit |
|---|---|
| BSU | Bartholin, Skene, urethral [glands]; basic structural unit; British standard unit |
| CFU-S, | CFUS colony-forming unit, spleen; colony-forming unit, stem cells |
| CRU | cardiac rehabilitation unit; clinical research unit |
| ECU | environmental control unit; extended care unit; extensor carpi ulnaris |