未生 is read as みしょう (mishou) and means unborn.
みしょう
mishou
みしょういぜん
before one's birth
みかくにんせいぶつ
cryptid (animal whose existence is unsubstantiated, e.g. the yeti)
せいぼつねんみしょう
dates of birth and death unknown
みめい
early dawn
みらい
(distant) future
みてい
not yet fixed
みせいねん
minor
みち
not yet known
みぜん
before it happens
まだ
(not) yet
みこん
unmarried
みばらい
unpaid