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% replaces any number of letters (la% - lake, lamp)_ replaces one letter (ca_ - car, cat)

Crossword clues for Cause of yawning, perhaps 7 letters:

BOREDOM: Cause of yawning, perhaps
ENNUI: Yawning cause, perhaps
BORES: Causes yawning perhaps
BORES: Causes to yawn, perhaps