Very; extremely. A colloquial adverb used to strongly emphasize degree.
このラーメン、めちゃおいしいよ。
This ramen is super tasty.
昨日はめちゃ疲れてすぐ寝てしまった。
I was so tired yesterday that I fell asleep right away.
今週はめちゃ忙しいから、昼休みも短い。
I'm extremely busy this week, so even lunch breaks are short.
めちゃ寒いからコートを着て行きなさい。
It's really cold, so put on a coat.
Used colloquially to mean 'absurd' or 'nonsensical' (often as めちゃ〈な〉…). This is spoken, and often replaced by めちゃくちゃ or めっちゃ.
そんな計画はめちゃな話だ。
That plan is absurd.
彼のいいわけはめちゃに聞こえた。
His excuse sounded ridiculous.
Indicates excess or extremeness (often as めちゃ〈な〉…). Similar to めちゃくちゃ/めっちゃ; colloquial and may vary by region.
その店はめちゃな量を出すので、食べきれないこともある。
That shop serves such huge portions that you sometimes can't finish them.
テストの難易度がめちゃで、合格者が少なかった。
The test was extremely difficult, and few people passed.