noun, noun which may take the genitive case particle 'no'
obvious; transparent; see-through
Describes something that is so obvious it's almost laughable, often used for lies, excuses, or attempts to hide something. Carries a slightly critical or mocking tone.
彼の言い訳は見え見えだった。
His excuse was so obvious.
あの嘘は見え見えだよ。
That lie is totally transparent.
明らか is a more formal and neutral word for 'obvious' or 'clear', while 見え見え is casual and often implies a clumsy attempt to deceive.
バレバレ is a very similar casual word meaning 'totally exposed' or 'found out', but it focuses more on the fact that something has been discovered, whereas 見え見え emphasizes that it was obvious from the start.
Reduplication of the stem 見え (from 見える 'to be visible'), creating an emphatic noun/adjective meaning 'plainly visible' or 'obvious'. The exact historical derivation is uncertain, but the pattern is common in colloquial Japanese.