| Mr | relative molecular mass |
|---|---|
| MW | Mallory-Weiss [syndrome]; mean weight; megawatt; microwave; Minot-von Willebrand [syndrome]; molecul... |
| MWD | microwave diathermy; molecular weight distribution |
| s | Greek lower case letter sigma; conductivity; cross section; millisecond; molecular type or bond; pop... |
| UHMW | ultrahigh molecular weight |