رَسَّ الهُوَى فِى قَلْبِهِ, and السُّقْمُ فِى جِسْمِهِ, [aor., accord. to the general rule, ـِ,] inf. n. رَسٌّ and رَسيسٌ, Love entered, and established itself, in his heart, and disease in his body; as alsoارسّ↓. (M.) [It seems also, from explanations of رَسُّ and رَسِيسٌ mentioned below, that one says رَسَّتِ الحُمَّى, meaning The fever commenced, or first touched a person.]

رَسٌّ The beginning, or commencement, of a thing. (Ḳ.) And hence, (Ḳ,) رَسُّ الحُمَّى, andرَسِيسُهَا↓, The beginning, or commencement, (M, A, Ḳ,) or first touch, (Ṣ,) of fever, (Ṣ, M, A, Ḳ,) before it becomes vehement, or severe; (A;) i. e., when the person attacked thereby stretches on account of it, and becomes languid in his body, and relaxed, or heavy, sluggish, or torpid, or confused in his intellect: (M, TA:) or the first that a man feels of the touch of fever, before it takes him forcibly, and becomes apparent. (Aṣ, TA.) Accord. to Fr, you say, أَخَذَتْهُ الحُمَّى بِرَسٍّ, meaning, The fever became settled in his bones. (TA.) [Hence also,] رَسُّ الحُبِّ, andرَسِيسُهُ↓, The beginning, or commencement, of love: (Ḳ:) or a remain, or relic, or trace, of love: (M:) orرَسِيسُ↓ الهَوَى signifies the first, or original, feeling (أَصْل) of love. (Aboo-Málik, TA.) [Hence also,] بَلَغَنِى رَسٌّ مِنْ خَبَرٍ The first of news reached me: (TA:) or somewhat of news reached me: (Ṣ, M:) [or news not true reached me: for,] accord. to AZ, you say, أَتَانَا رَسٌّ مِنْ خَبَرٍ, andرَسِيسٌ↓ مِنْ خَبَرٍ, meaning, News not true came to us: (TA:) orرَسِيسٌ↓ [alone] signifies news not true. (Ḳ.)