Entry
  1. Na-adjective (keiyodoshi), Noun, Adverb (fukushi)

    madly in love; head over heels; fanatically doting; spellbound

    Onomatopoeic or mimetic word

    私はもうあなたに夢中、メロメロなのよ。
    I'm stuck on you - really far gone.
  2. collapsed; out of spirits

Also written めろめろ

Pitch on OJAD