SENNIGHT Meaning of SENNIGHT in English /sen"uyt, -it/ , n. Archaic.a week. Also, se'nnight . [ bef. 1000; ME sevenyht, seoveniht ( e ), sennyght, etc., OE seofon nihta. See SEVEN, NIGHT ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012