'gasmask' definitions:

Definition of 'gasmask'

(from WordNet)
noun
A protective mask with a filter; protects the face and lungs against poisonous gases [syn: gasmask, respirator, gas helmet]

Definition of 'gasmask'

From: GCIDE
  • gasmask \gasmask\ n. a mask with a filter which protects the face and lungs against poisonous gases. It is used in warfare, and also by police to allow them to effectively use tear gas or other disabling gas to disperse a crowd or force fugitives to leave a building.
  • Syn: respirator, gas helmet. [WordNet 1.5]