Answer: coombs

AnswerCrossword Clue
COOMBSValleys, in Britain
coombsgrease from bearings, axles, etc.
coombssoot; coal dust; smut
coombsdust, esp. sawdust or dust from a gristmill
coombsnarrow valley or deep hollow, esp. one enclosed on all but one side
coombsCOOMB, a narrow valley, also COMBE, COOMBE