Nope, this is not a nouveau cusine version of the Tamil dosa flatbread.
It’s Bahasa Maluku for “sinner”.
I heard it a lot in the week and a half I spent on Seram Island. It applies for a lazy man, or for a man who has just given a woman a once over with his eyes.
Berdosa is the Indonesian action verb “to sin”. Su is malukan slang for already.
Perhaps this is common in all of Eastern Indonesia but Malukan street talk usually means words without suffixes. Their counterparts from the western end of the archipelago drop the s in sudah (already/over) when chatting with friends. Malukans say su.