Meaning of “Fujoshi(腐女子)”

“Fujoshi(腐女子)” means girls who like BL.
“Fu(腐)” means rot and “Joshi(女子)” means girls.
This is a kind of wordplay based on the term fujoshi (婦女子), meaning women.
*The “fu(婦)” in fujoshi (婦女子) comes from the character for “married woman” or “lady” (婦), as in fujin (婦人).
The reason the slang uses the word “Fu(腐)” (rot or decay) is said to come from a self-deprecating expression by these women, who jokingly say things like, “My brain must be rotten for imagining BL.”
By the way, As they get older, fujoshi(腐女子) become “kifujin(貴腐人)”.
“kifujin(貴腐人)” is also a kind of wordplay based on the term kifujin (貴婦人) which means lady.
The reason? Another self-deprecating one: they feel they can no longer call themselves “Joshi(女子)” which means girls.

Example Conversation

A: I heard the new minister is “rotten.”
B: Huh? What do you mean?
A: I mean she is “Kifujin(貴腐人)”.. or rather, maybe “Kifujin(貴婦臣)”.
B: Ohhh, that kind of “rotten”? lol

A: 今度の大臣は腐ってるらしいよ
B: え？どういうこと？
A: 貴婦人ってことだよ。いや、貴婦臣か…
B: そっちの意味かw

*Kifujin(貴婦臣)’s Jin(臣) is from Daijin(大臣) which menas minister.