siphonophore

1 of 2

noun

si·​pho·​no·​phore sī-ˈfä-nə-ˌfȯr 

ˈsī-fə-nə-

: any of an order (Siphonophorae) of colonial, free-swimming or floating, marine hydrozoans (such as the Portuguese man-of-war) that are mostly delicate, transparent, and colored and have zooids possessing specialized functions (such as feeding or locomotion)

… startling brilliance is often seen among siphonophores, gelatinous colonial animals whose different members work in unison.

—William J. Broad

Most siphonophores are small, transparent creatures of the open sea. They float at the surface among the plankton or swim actively, usually at shallow depths. As carnivores, they capture small planktonic animals in their net of tentacles.

—Stephen Jay Gould

Siphonophora

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plural noun

Si·​pho·​noph·​o·​ra

ˌsīfəˈnäfərə

: an order of Hydrozoa consisting of various free-swimming or floating pelagic mostly delicate transparent and often showily colored forms that are usually regarded as compound animals composed of zooids modified to perform various functions for the colony (such as feeding, defense, locomotion), that sometimes have two or more zooids in the form of a bell which by their contractions cause the colony to swim, and that often have a hollow float which keeps the colony afloat compare diphyes , porpita , portuguese man-of-war , velella

siphonophoran

¦⸗⸗¦⸗⸗rən

adjective or noun

siphonophore

sīˈfänəˌfō(ə)r 

ˈsīfənəˌf-

noun

plural -s

siphonophorous

¦sīfə¦näfərəs

adjective

Examples of siphonophore in a Sentence

Recent Examples on the Web

Noun

With their long stinging tentacles, these big siphonophores do seem like the most likely suspects. — Matthew Wills, JSTOR Daily, 3 Apr. 2026

The deep sea is rich with organisms armed with stinging cells, like jellyfish and siphonophores. — Scott Travers, Forbes.com, 26 Mar. 2026

Somewhere over the course of their evolution, the class of hydrozoans — which includes certain kinds of jellyfish, hydras, and colonial siphonophores such as the Portuguese man-of-war — lost the genes that operate circadian clocks in the rest of the animal kingdom. — Marlowe Starling, Quanta Magazine, 20 Mar. 2026

The Portuguese man-of-war is a siphonophore, meaning it is made up of a colony of organisms that each have a special function, according to the Texas Department of Parks and Wildlife. — Caroline Wilburn, Houston Chronicle, 9 Mar. 2026

Word History

Etymology

Noun

ultimately from Greek siphōn + pherein to carry — more at bear

Plural noun

New Latin, from siphon- + -phora; probably from the hollow float

First Known Use

Noun

circa 1842, in the meaning defined above

Rhymes for siphonophore

• counteroffer
• spermatophore
• coffer
• offer
• proffer
• scoffer

Medical Definition

siphonophore

noun

si·​pho·​no·​phore sī-ˈfän-ə-ˌfō(ə)r  ˈsī-fə-nə- 

-ˌfȯ(ə)r

: any of an order (Siphonophorae) of compound free-swimming or floating pelagic hydrozoans see portuguese man-of-war