noun
three-year period of bad luck (in rokusei senjutsu)
A term from 六星占術 (rokusei senjutsu), a form of fortune-telling. Refers to a three-year cycle of misfortune. Often used in discussions of luck and life planning.
See also: 六星占術
今年から大殺界に入るらしい。
Apparently I'm entering a three-year period of bad luck starting this year.
大殺界の間は無理をしないほうがいいと言われている。
It's said that you shouldn't push yourself too hard during the three-year bad luck period.