خَانِسٌ
1.
Going back or backwards; receding; retreating; retiring; or retrograding: or remaining behind; holding back; hanging back; or lagging behind: synonym مُتَأَخِّرٌ: plural خُنَّسٌ. (TA.)
2.
[Hence,] الخُنَّسُ, (in the Qur'an, 81:15, S,) (tropical:) The stars; (S, K;) i. e., all of them; because they retire, or hide themselves, (تَخْنُسُ,) at setting; or because they become concealed in the day-time: (S:) or the planets: (S, K:) or the five stars, Saturn, Jupiter, Mars, Venus, and Mercury: (Fr, S, K, Jel:) because they return, (تَخْنُسُ, i. c., تَرْجِعُ, Jel,) in their course: (Fr, S, Jel:) when you see a star [thereof] in the end of a sign of the zodiac, it returns to the beginning of it: (Jel:) or because of their retrogression; for they are the erratic stars (الكَوَاكِبُ المُتَحَيَّرِةُ), which [at one time appear to] retrograde, and [at another time to] pursue a direct [and forward] course: (S:) or because they sometimes return (تخنس) in their course until they become concealed in the light of the sun: (TA:) or because they hide themselves, as the devil does at the mention of God. (K, TA.)
3.
And hence, i. e., from خَانِسٌ in the sense of مُتَأَخِّرٌ, the saying in a tradition of El- Hajjáj, الإِبِلُ ضِمَّرٌ خِنَّسٌ, meaning, (assumed tropical:) [Camels are lean, and lank in the belly, and] patient of thirst. (TA.)
4.
And اللَّيَالِى الخُنَّسُ
The three nights of the lunar month during which the moon retires [from view]. (TA.)