That emits flame from the mouth or nostrils(adjective)
Caustic, vitriolic or scathing(adjective)
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Use "fire-breathing" in a sentence
"Last fall I was shooting my .45/70 Guide gun offhand, using Garrett Cartridges 'fire-breathing cast-lead loads, and all my shots hit in a nice tight group about a foot to the right of where I was aiming."
"He fell into a deep cave and landed between two fire-breathing dragons."
"Of what potency the fearful rites and masked mysteries of shamanism, when daily that living wonder, the steamboat, coughed and spluttered up and down the Yukon in defiance of all law, a veritable fire-breathing monster?"