Antonyms for the phrase "most crystal clear" includes, but is not limited to; obscure, vague, muddled, unclear, hazy, foggy, indistinct, ambiguous, murky, fuzzy, and perplexing. In contrast with the clarity associated with "most crystal clear," these antonyms connote a lack of definition, quality, and precision. The opposite of crystal clear are words that imply that something is hard to understand. Rather than being apparent and apparent, as clear things are, the opposite of clarity is associated with confusion and lack of perception. It is worth noting that all of these antonyms have degrees of nuance, and the appropriate opposite will depend on the context of use.