You can think of marchioness as one title with a woman standing in it. The title is a fixed thing, like a seat with a name on it: the Marchioness of somewhere. What changes from case to case is only how the woman came to be sitting there. Usually she married into it. Sometimes it passed to her and it was always hers. And once, in old stories, someone put a girl who scrubbed floors in that grand-sounding seat as a joke.
The supplied Wiktionary entry derives marchioness from Medieval Latin marchionissa, the feminine of marchion, from Late Latin marca, from Frankish markon and Germanic marko, meaning an area, edge or border. So the title can be pictured as starting from land at the border, and the woman's form of the word is built on the man's by adding a feminine ending.
資料裡的 Wiktionary 條目說 marchioness 來自中世紀拉丁文 marchionissa，是 marchion 的陰性形；再往前是晚期拉丁文 marca，源自法蘭克語 markōn、日耳曼語 markō，意思是「地界、邊緣、邊境」。可以想成：這個爵位的起點是邊境上的一塊地，而女性形式是在男性字的後面加上陰性字尾造出來的。
Wiktionary entry supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1262602487)
Two branches
爵位與稱謂
這一家就是頭銜本身，兩個意思共用同一個字、同一種寫法。差別只在頭銜從哪裡來，而英文靠 in her own right 這句話把兩者分開。
noun · C1
The wife of a marquess (also written marquis), which is one of the ranks of the British nobility. She is usually called the Marchioness of the place the family title comes from.
侯爵夫人
舊小說裡的戲稱
這一家可以想成把那把氣派的椅子搬到最不搭的人身上。落差本身就是笑點，也可能帶著心疼或刻薄。資料標成俚語而且已經不用，所以把它當成讀舊書時的認字，不是今天可以用的說法。這是一種比喻上的延伸，不是另一條歷史來源。
noun · C2
In older writing, a playful name for a girl or woman servant who did every kind of work in a house. The grand title was given to someone who had no rank at all. The source marks this use as slang and obsolete, so English speakers do not use it this way now.
舊小說裡對女僕的戲稱