مُسَاهَرَةٌ

signifies The being sleepless, or awake, with another: (KL, and Har p. 329:) [and the vying with another in remaining sleepless or awake:] and [like إِسْهَارٌ, but I think this doubtful,] the making [one] sleepless or awake. (KL.) ساهر النُّجُومَ means He passed the night sleepless like as do the stars. (Har ubi suprà.)