Unburned carbon (smoke) from a steam or diesel locomotive, or multiple unit.
Bits of rubber which are shed from tires during a race and collect off the racing line, especially on the outside of corners (cf. marbles).
A glue or paste made from starch.
Low cloud, fog or smog.
To stick, like boots in mud
A mixture of gaseous hydrocarbons associated with petroleum deposits; mostly methane with smaller amounts of ethane, propane and butane; principally used as a fuel.