大姨媽

See also: 大姨妈

Chinese

		big, eldest	auntie
trad. (大姨媽)		大	姨媽
simp. (大姨妈)		大	姨妈

The euphemistic sense was originally a Cantonese colloquialism.

大姨媽

(chiefly southern dialects) eldest maternal aunt (mother's eldest sister older than one's mother)
(euphemistic, slang, humorous) Aunt Flo (a personification of the menstrual period or menstruation)
來大姨媽／来大姨妈 ― lái dàyímā ― to be on one's period

If one's mother is the eldest of the sisters, her oldest sister is not reckoned as a 大姨媽 but as 二姨.

Dialectal synonyms of 月經 (“menstruation; period”) [map]

Variety	Location	Words edit
Formal (Written Standard Chinese)		月經, 月信, 月事, 潮信 euphemistic
Northeastern Mandarin	Beijing	月經, 例假
	Taiwan	月經, 月事, 好朋友, 大姨媽
	Singapore	月經, 大姨媽
Jilu Mandarin	Jinan	月經, 例假
Jiaoliao Mandarin	Yantai (Muping)	經脈兒
Central Plains Mandarin	Wanrong	月經, 身上
	Xining	例假
	Yanqi	哈兒足 Hui
Lanyin Mandarin	Yinchuan	哈兒足 Hui
Southwestern Mandarin	Wuhan	好事
	Dagudi (Maliba)	月經, 姊妹
	Reshuitang (Longling)	大姨媽
	Mae Salong (Lancang)	月經, 大姨媽
	Mae Sai (Tengchong)	月經
Cantonese	Guangzhou	大姨媽, 姑婆, 例假
Cantonese	Hong Kong	月經, 大姨媽, M
Gan	Lichuan	身上
Hakka	Miaoli (N. Sixian)	月期
	Pingtung (Neipu; S. Sixian)	月期
	Hsinchu County (Zhudong; Hailu)	月期
	Taichung (Dongshi; Dabu)	月期
	Hsinchu County (Qionglin; Raoping)	月期
	Yunlin (Lunbei; Zhao'an)	月期
Jin	Taiyuan	月經
Southern Min	Xiamen	月經
	Quanzhou	月經
	Zhangzhou	月經
	Kaohsiung	月經
	Yilan	月經
	Changhua (Lukang)	月經
	Taichung	月事
	Taichung (Wuqi)	月經
	Tainan	mè-sù, 月經, 驚儂個
	Taitung	月經
	Hsinchu	月經
	Penghu (Magong)	月經
	Singapore (Hokkien)	月經
	Manila (Hokkien)	月經
	Jieyang	老馬
Wu	Shanghai	月經, 經水 dated, 老朋友, 老鬼三, 大姨媽
	Ningbo	大尿, 月家
	Wenzhou	身上來