The story
From Portuguese (adjective) + man-of-war, from the resemblance of the organism’s float to a former Portuguese warship at full sail.
Etymology from Wiktionary, CC BY-SA 4.0.
Portuguese man-of-war
Por·tu·guese man-of-warToday it means: Physalia physalis, a marine cnidarian consisting of a floating colony of hydrozoans attached to a float, superficially resembling a jellyfish. Full definition →