| M/C | male, castrated [animal] |
|---|---|
| MEA | male-enhanced antigen; Medical Exhibition Association; mercaptoethylamine; monoethanolamine; multipl... |
| M/F | male/female [ratio] |
| M& | F male and female; mother and father |
| MIT | Massachusetts Institute of Technology; male impotence test; marrow iron turnover; melodic intonation... |