Meaning

noun 12 o'clock at night; the middle of the night

originFrom Middle English midnight, from Old English midniht, from Proto-Germanic *midjanahts (“midnight”), equivalent to mid- + night. Cognate with Saterland Frisian Midnoacht (“midnight”), Old High German mittinaht (“midnight”), Danish midnat (“midnight”), Swedish midnatt (“midnight”), Icelandic miðnætti (“midnight”). Compare also Saterland Frisian Middernoacht (“midnight”), Dutch middernacht…

Etymology from Wiktionary, CC BY-SA 3.0