Answer:

gunk

Answer	Crossword Clue
GUNK	Greasy goo
GUNK	Greasy residue
GUNK	Icky stuff

GUNK	Slime
GUNK	Greasy glop
GUNK	Thick, messy stuff
GUNK	Oil filter accumulation
GUNK	Sticky goo
GUNK	Goop
GUNK	Messy stuff
GUNK	Greasy dirt

GUNK	Sticky residue
GUNK	Engine fouler
GUNK	Sludgy stuff
GUNK	Sticky stuff
GUNK	Gooey dirt
GUNK	Muck
GUNK	Sludge: Slang.
GUNK	Sticky mess.

GUNK	Greasy stuff
GUNK	Goo
GUNK	Crud
GUNK	Unwanted buildup
GUNK	Sticky matter
GUNK	Engine buildup
GUNK	Residue in a bathtub drain
GUNK	Icky residue

GUNK	Slimy crud
GUNK	Thick, messy substance
GUNK	Slop

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.