اعتلمهُ

2.
اعتلم said of water, It flowed (K, TA) upon the ground. (TA.)
3.
And said of lightning it means لَمَعَ فى العلم [apparently فِى العَلَمِ, and, if so, meaning It shone, shone brightly, or gleamed, in, or upon, the long mountain]: a poet says,
بَلْ بُرَيْقًا بِتُّ أَرْقُبُهُ
لَا يُرَى إِلَّا إِذَا اعْتَلَمَا
[But a little lightning, in watching which I passed the night, not to be seen save when it shone, &c.]. (TA.)

Perseus ID: n30344