لغو3 لَاغَاهُ He jested, or joked, with him; inf. n. مُلَاغَاةٌ. (A, TA.) You say, لَاغَاهُ فِى البَيْعِ. (A, TA, art. كيس.) لَغْوٌ, applied to speech, &c., Nought; of no account; (M, K;) unprofitable. (M.) b2:  اليَمِينُ اللَّغْوُ: see KT, voce يَمِينٌ.اللُّغَةُ The genuine language of the Arabs; which is the classical language.لُغَوِىٌّ Of, or relating to, the genuine language of the Arabs. مَعْنًى لُغَوِىٌّ A genuine lexicological meaning.لُغَيَّةٌ A word of weak authority. (TA, voce جِرَاب, et passim.) لَاغٍ: see مَائِرٌ.