磨牙 [－－]

Jyutping mo4 ngaa4
Pinyin mó yá

Definitions (CC-CEDICT)
  1. to grind one's teeth (during sleep)
  2. pointless arguing
  3. (coll.) molar
Definitions (粵典–words.hk)
  1. 名詞
    （​通常​係​無意識​咁​）​將​上下​排牙​齒​相互​摩擦
    bruxism
  2. 近義詞
    扤牙
Definitions (Wiktionary)
  1. verb, dialectal
    to argue pointlessly; to indulge in idle talk
  2. verb
    to grind one's teeth (during sleep)
    (syn.) 哺齿, 啮牙, 齧牙, 咬喙齿, 咬喙齒根, 哺齒, 咬喙齿根, 咬喙齒
  3. noun, Mainland-China
    molar
    (syn.) 後層 GT, 槽牙, 榫頭牙, 臼齒, 大層, 大牙, 後層, 後層齒, 大牙齒, 牙頭母, 後槽牙, 大層齒, 牙槽齒, 大牙板