firedamp

From fire + damp with 'damp' not in the usual sense of 'moist' but old German, modern Dutch, Danish 'damp' as steam or vapour, hence a gas liable to catch fire.

1. 01
   derived from *dampaz✻
2. 02
   derived from dampen
3. 03
   inherited from dampen — “to stifle; suffocate”
4. 04
   compounded as firedamp — “fire + damp”