What does clag mean?
Clag is an informal English noun referring to sticky, clogging matter — most commonly wet mud that clings to boots, wheels, or paws, but also the gummy residue left behind by old tape or glue. It also functions as a verb meaning to stick together or become gummed up, as in machinery or a bicycle chain fouled with grime. The word is chiefly British and Australian in everyday use and belongs firmly to colloquial register rather than formal prose; it carries a mildly unpleasant connotation, evoking the frustration of things sticking where they shouldn't. The related adjective 'claggy' describes ground or surfaces that are damp and adhesive underfoot. In Australian slang, clag has an additional, unrelated-feeling sense: a thunderstorm, presumably from the heavy, oppressive quality of such weather. Compact and vivid, clag is a useful word for anyone describing muddy paths, messy adhesives, or anything that refuses to come clean.
Sticky or clogging matter, such as wet mud or the residue left by adhesive.
"The bike's gears were jammed solid with clag."
Informal; chiefly British and Australian. In Australian slang, also used to mean a thunderstorm.
To stick together, clog, or encumber with sticky material.
"Wet snow clagged to the dog's fur all the way home."
Usually used with an object or as 'clag up'.
Standard plural; often uncountable when referring to mud or residue in general.
"There were thick clags of mud on every step."
In Australian slang, 'clag' can also mean a thunderstorm — so the same word covers both the mud underfoot and the weather that put it there.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of clag
Clag is of obscure origin, first recorded in English around the sixteenth century as a dialectal term for something that sticks or clogs. It appears to be related to or formed alongside the adjective 'claggy', which likewise describes sticky, muddy consistency. The word has survived mainly in regional British speech and has flourished in Australian English, where both its muddy sense and its slang sense of a thunderstorm remain current.
Related word forms
How clag is actually used
Clag is an informal word, most at home in British and Australian English; it is rarely heard in formal writing. In Australian slang it additionally denotes a thunderstorm, a sense not generally known outside Australia. The derived adjective 'claggy' describes ground or surfaces that are sticky or muddy.
Easily confused with clag
"Clog" means to block or obstruct (or a wooden shoe), while "clag" specifically refers to sticky mud or adhesive matter and the act of sticking or becoming gummed up.