What does unclog mean?
“Unclog” usually means to remove an obstruction from something, especially a pipe, drain, sink, or other passage. As a transitive verb, it takes the blocked object directly: one can unclog a drain or unclog a pipe. It may also be used intransitively when a passage becomes clear. The word has a practical, everyday tone and often implies restoring normal flow rather than dismantling or deeply cleaning the object. In occasional adjective use, unclog describes something already free from an obstruction. Its compact construction comes from the productive prefix un-, meaning “not” or “reverse of,” attached to clog: the verb says, in effect, to undo the condition of being clogged. Although unclog can describe clearing a physical blockage, it also appears figuratively in contexts such as easing congestion or making progress easier. Dictionaries differ over how common the adjective is, but the verb is established in both British and American English.
To remove an obstruction from a pipe, drain, sink, or similar passage; also used intransitively to become clear.
"The plumber unclogged the drain and the water flowed away normally."
Common in both British and American English; the transitive construction with a blocked object is the most frequent usage.
Free from obstruction or blockage.
"By morning, the pipe was unclog again."
Less common than the verb and often used predicatively rather than attributively.
From a blocked drain to a crowded pathway, unclog does what its two small pieces promise: reverse the stop.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does unclog come from?
Unclog was formed in English by combining the prefix un- with clog. The prefix reverses or removes the condition expressed by the base word, producing the meaning “to undo being clogged.” Related forms include clogger and cloggy, which share the same root.
Related word forms
How unclog is actually used
The verb is neutral and common in everyday and professional contexts. The adjective is less frequent and is often used predicatively, as in “the pipe is unclog.”
Easily confused with unclog
To unclog is to remove an obstruction, whereas to clog is to block or obstruct something.