A colloquial variant of 'to iu ka' used to rephrase or add nuance—similar to 'or rather' / 'I mean'. Common in casual speech.
今日は疲れた、ちゅーかもう限界かも。
I'm tired today—or rather, I might already be at my limit.
彼の説明は分かりやすい、ちゅーか簡潔で助かる。
His explanation is clear—or rather, concise, which helps.
その映画、面白かった、ちゅーか考えさせられたよ。
That movie was good—or rather, it made me think.