Portuguese man-of-war

noun

plural Portuguese man-of-wars also Portuguese men-of-war

: any of a genus (Physalia of the family Physaliidae) of large, tropical and subtropical, pelagic, siphonophore hydrozoans having a crested bladderlike float which bears the colony comprised of three types of zooids on the lower surface with one of the three having nematocyst-equipped tentacles

Illustration of Portuguese man-of-war

• Portuguese man-of-war

Examples of Portuguese man-of-war in a Sentence

Recent Examples on the Web

Students from Tohoku University have discovered a brand-new species of the venomous Portuguese man-of-war. —Pranjal Malewar, New Atlas, 13 Nov. 2025

What to know about the seafarers The blobs are not jellyfish but colonies of polyps similar to the Portuguese man-of-war, according to JellyWatch. —Daniella Segura, Sacbee.com, 23 Apr. 2025

Though interesting to look at, the Portuguese man-of-war’s venom can be deadly to small fish and painful to humans, according to the National Oceanic and Atmospheric Administration. —Natalie Demaree, Miami Herald, 11 Apr. 2025

Box jellyfish, Portuguese man-of-war, lion’s mane and sea nettle are among highly venomous jellyfish species whose stings require immediate medical attention, per UF Health. —Caroline C. Boyle, USA TODAY, 8 July 2024

Blue dragons, known scientifically as Glaucus atlanticus, sail on the surface of the ocean feeding on toxins from the Portuguese man-of-war and other jellyfish-like organisms. —Priscilla Thompson, NBC News, 9 Mar. 2024

Nyad was blown off course and contented with shoulder pain, asthma and stings from jellyfish and Portuguese man-of-war. —Jack Smart, Peoplemag, 3 Nov. 2023

Saving Desert Tortoises from Extinction To view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 video In July, village lifeguards used five-gallon buckets to collect Portuguese man-of-wars that had washed up on the sand. —Emma Allen, The New Yorker, 14 Aug. 2023

Waking to the Tao surrounded by the pink poisonous sails of Portuguese man-of-wars as far as the eye could see. —Stephen Colbert, Outside Online, 5 Apr. 2011

Word History

First Known Use

1707, in the meaning defined above

Rhymes for Portuguese man-of-war

• abhor
• abor
• adore
• afore
• ardour
• ashore
• backdoor
• before
• bookstore
• candour
• centaur
• claymore

Kids Definition

Portuguese man-of-war

noun

plural Portuguese man-of-wars also Portuguese men-of-war

: any of several large colonial invertebrate animals that are hydrozoans and float on the surface of the sea by means of a large gas-filled structure like a bag and have long tentacles capable of delivering a painful sting

Medical Definition

Portuguese man-of-war

noun

Por·​tu·​guese man-of-war ˌpȯr-chə-ˌgēz-ˌman-əv-ˈwȯr 

plural Portuguese man-of-wars -ˈwȯrz  also Portuguese men-of-war -ˌmen-əv-ˈwȯr 

: any siphonophore of the genus Physalia including large tropical and subtropical oceanic forms having a crested bladderlike float which bears a colony comprised of three types of zooids on the lower surface with one of the three having stinging tentacles