Viscous gunk (6)
I believe the answer is:
sludge
(Other definitions for sludge that I've seen before include "Dirty oil; soft wet mud" , "Muddy sediment" , "Melting snow" , "Thick, soft, wet mud" , "'Muck, slime (6)'" .)
I believe the answer is:
sludge
(Other definitions for sludge that I've seen before include "Dirty oil; soft wet mud" , "Muddy sediment" , "Melting snow" , "Thick, soft, wet mud" , "'Muck, slime (6)'" .)