Senses
三九 coldest days of winter
The third nine-day period after the winter solstice, from the 19th to the 27th day, usually the coldest time of the year.
三九 high officials
(literary) Refers collectively to the Three Councilors and Nine Ministers of ancient China.
三九 three kinds of leeks
(literary) Refers to three preparations of leeks, symbolizing a frugal or poor lifestyle.