لُثْفَةٌ The changing, in pronunciation, س into ث, or ر into غ or ل, (Ṣ, Ḳ, Mṣb,) and the like: (Mṣb:) or, one letter into another. (Az, in Mṣb, Ḳ.) Also, A word mispronounced; as when a word is said to be لُغَةٌ أَوْ لُثْفَةٌ a dialectal variant or a word mispronounced.