Where does “swim nappy” come from?

swim nappy (English) comes from English nappy, from English NAP, from French napper, from French -er, from English -er, from Middle English -er, from Old French -er, from Latin -āre — he, she.

Ancestry of “swim nappy”, step by step

swim nappy traces back through two separate lines of ancestry.

via English nappy

StepLanguageWordMeaning
1EnglishnappyAn absorbent garment worn by a baby who does not...
2EnglishNAPAcronym of non-aggression principle; Acronym of...
3Frenchnapperto cover
4French-erForms infinitives of first-conjugation verbs
5English-erA person or thing that does an action indicated...
6Middle English-eragentive suffix; agent noun suffix
7Old French-erAlternative form of -ier, verbal suffix;...
8Latin-ārefirst conjugation
9Proto-Italic-āōForms primarily denominative verbs
10Proto-Indo-European-eh₂yétiCreates iterative/ frequentative/ intensive...
11Proto-Indo-European-yétiCreates intransitive, often deponent,...
12Proto-Indo-Europeanyé-
13Chichewaiyehe, she

via English swim

StepLanguageWordMeaning
1EnglishswimTo move through the water, without touching the...
2Middle Englishswime
3Old Englishswimaa swoon, swimming in the head
4Proto-West Germanicswimmanto swim
5Proto-Germanicswimmanąto be unsteady; to swim; float
6Proto-Indo-Europeanswem(bʰ)-to bend, turn, swing; to be unsteady, move, swim
Every word from Chichewa iye