adverb, adverb taking the 'to' particle
with a squeaking sound (of metal)
Mimetic word describing a high-pitched, repetitive squeaking or creaking noise, typically from metal parts rubbing together.
古い自転車のチェーンがキコキコと鳴る。
The chain of the old bicycle squeaks.
ドアを開けるたびにキコキコいう。
The door makes a squeaking sound every time I open it.
Onomatopoeic formation from the sound of metal squeaking.