- dangerous (adj.)
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- early 13c., "difficult, arrogant, severe" (the opposite of affable), from Anglo-French dangerous, Old French dangeros (12c., Modern French dangereux), from danger (see danger).
In Chaucer, it means "hard to please, reluctant to give;" sense of "full of danger, risky" is from late 15c. Other words used in this sense included dangersome (1560s), dangerful (1540s). Related: Dangerously.