Where does “man shower” come from?

man shower (English) comes from English MAN, from English manual, from Middle English manuel, from Anglo-Norman manuel, from Old French manual, from Latin manuālis, from Latin manus, from Proto-Italic manus — human being; man; hand.

Ancestry of “man shower”, step by step

man shower traces back through two separate lines of ancestry.

via English MAN

StepLanguageWordMeaning
1EnglishMANInitialism of Metropolitan Area Network
2EnglishmanualA handbook; A booklet that instructs on the usage...
3Middle Englishmanuel
4Anglo-Normanmanuelmanual; done with the hands; handle; manual;...
5Old Frenchmanual
6Latinmanuālishand
7Latinmanushand; bravery, valor; violence, fighting
8Proto-Italicmanushand
9Proto-Indo-Europeanman-human being; man; hand

via English baby shower

StepLanguageWordMeaning
1Englishbaby showerA party celebrating the pending or recent birth of a child, involving guests giving gifts (typically babycare items) to the parent(s)
2EnglishbabyA very young human, particularly from birth to a...
3Middle EnglishbabyA child or baby
4Middle English-yDesignates an adjective, in many cases formed by...
5Old English-iġ-y, -ic
6Proto-West Germanic-gForms adjectives from nouns and verbs with a...
7Proto-Germanic-gaz-y
8Proto-Indo-European-ḱos-y, -ic
Every word from Proto-Indo-European man-