大姨妈

mother's eldest sister (older than one's mother) / (coll.) (euphemism) Aunt Flo (i.e. menstrual period)

see 大夫[dai4 fu5]

big; large; great / older (than another person) / eldest (as in 大姐[da4 jie3]) / greatly; freely; fully / (dialect) father / (dialect) uncle (father's brother)

aunt (mother's eldest sister) / (respectful term of address for a woman who is about the age of one's mother)

mother's sister / aunt

(coll.) mother's sister / maternal aunt

ma / mom / mother