(as) clear as mud
US /əz klɪr əz mʌd/
UK /əz klɪr əz mʌd/

1.
sama sekali tidak jelas, sangat sulit dimengerti
very difficult to understand; not clear at all
:
•
His explanation of the new policy was as clear as mud.
Penjelasannya tentang kebijakan baru itu sama sekali tidak jelas.
•
The instructions for assembling the furniture were as clear as mud, so I had to guess.
Petunjuk untuk merakit furnitur itu sama sekali tidak jelas, jadi saya harus menebak.