adverb taking the 'to' particle
gurgling down; being sucked in; caving in suddenly
Mimetic word describing a sudden, forceful inward movement or collapse, often with a liquid or hollow sound. Used adverbially with と.
栓を抜くと、水がごぼっと流れ出した。
When I pulled the plug, the water gurgled out.
彼は沼に足を取られ、ごぼっと沈み込んだ。
His foot got caught in the swamp and he sank in with a gulp.