[lahyt-ning] 
noun, verb, -ninged, -ning, adjective | 1. | a brilliant electric spark discharge in the atmosphere, occurring within a thundercloud, between clouds, or between a cloud and the ground. |
| 2. | to emit a flash or flashes of lightning (often used impersonally with it as subject): If it starts to lightning, we'd better go inside. |
| 3. | of, pertaining to, or resembling lightning, esp. in regard to speed of movement: lightning flashes; lightning speed. |
| light·ning (līt'nĭng) n.
To discharge a flash of lightning. adj. Moving or occurring with remarkable speed or suddenness. [Middle English, gerund of lightnen, to illuminate, from lighten, from Old English līhtan; see leuk- in Indo-European roots.] |
Lightning
frequently referred to by the sacred writers (Nah. 1:3-6). Thunder and lightning are spoken of as tokens of God's wrath (2 Sam. 22:15; Job 28:26; 37:4; Ps. 135:7; 144:6; Zech. 9:14). They represent God's glorious and awful majesty (Rev. 4:5), or some judgment of God on the world (20:9).
lightning
In addition to the idiom beginning with lightning, also see like greased lightning; quick as a wink (lightning).
nɪŋ