Also,

light·ning

ˈlītniNG/
noun
noun: lightning
1.
the occurrence of a natural electrical discharge of very short duration and high voltage between a cloud and the ground or within a cloud, accompanied by a bright flash and typically also thunder.
"a tremendous flash of lightning"




light·en·ing
ˈlītn-iNG,ˈlītniNG/
noun
noun: lightening; plural noun: lightenings

• a drop in the level of the uterus during the last weeks of pregnancy as the head of the fetus engages in the pelvis.