Where does “Portuguese man-of-war” come from?

Portuguese man-of-war (English) comes from English Portuguese, from Portuguese português, from Old Portuguese portugaes, from Late Latin portucalensis, from Latin Portucale, from Latin Portus Cale, from Latin Portus, from Proto-Italic portus — passed , crossed.

Portuguese man-of-war (English): Physalia physalis, a marine cnidarian consisting of a floating colony of hydrozoans attached to a float, superficially resembling a jellyfish

Definitions

  1. Physalia physalis, a marine cnidarian consisting of a floating colony of hydrozoans attached to a float, superficially resembling a jellyfish

Ancestry of “Portuguese man-of-war”, step by step

Portuguese man-of-war traces back through two separate lines of ancestry.

via English Portuguese

StepLanguageWordMeaning
1EnglishPortugueseOf or pertaining to the region of Portugal; Of or...
2PortugueseportuguêsPortuguese; Portuguese person; Portuguese...
3Old PortugueseportugaesPortuguese; a Portuguese person
4Late Latinportucalensis
5LatinPortucalePortugal
6LatinPortus CaleOporto
7LatinPortus” or, later, “Portus Rōmae”}} Portus large artificial harbour of Ancient Rome
8Proto-Italicportusharbour
9Proto-Indo-Europeanpértuscrossing
10Proto-Indo-Europeanper-before, in front; first; to go through
11Proto-Indo-Europeanpr̥tóspassed , crossed

via English man-of-war

StepLanguageWordMeaning
1Englishman-of-warUsed other than with a figurative or idiomatic...
Every word from Proto-Indo-European pr̥tósEvery word from Proto-Indo-European per-Every word from Proto-Indo-European pértus