Antonyms of verb unclog

1 sense of unclog

Sense 1
unclog -- (become or cause to become unobstructed; "The chemical that we poured down the drain unclogged it")
       Antonym of clog (Sense 1)
      => clog, choke off, clog up, back up, congest, choke, foul -- (become or cause to become obstructed; "The leaves clog our drains in the Fall"; "The water pipe is backed up")

Synonyms/Hypernyms (Ordered by Estimated Frequency) of verb unclog

1 sense of unclog

Sense 1
unclog -- (become or cause to become unobstructed; "The chemical that we poured down the drain unclogged it")
       => free, disengage -- (free or remove obstruction from; "free a path across the cluttered floor")