-imperceptibly;unconsciously;unwittingly;unknowingly;notknowingandnotfeeling;withoutone'snoticingit:
Theyhadagoodsleepofafewhourswithouttheirnoticingit,untiltheeastwasalreadybeginningtogrowbright.他们睡了好几个小时,不知不觉,东方已破晓了。
Threemonthshavepassedbeforeweknewit.不知不觉已过了三个月。