superfluid

American  

[soo-per-floo-id] / ˌsu pərˈflu ɪd /

noun

1. a fluid that exhibits frictionless flow, very high heat conductivity, and other unusual physical properties, helium below 2.186 K being the only known example.

---

adjective

1. of or relating to a superfluid.

superfluid British  

/ ˌsuːpəˈfluːɪd /

noun

1. physics a fluid in a state characterized by a very low viscosity, high thermal conductivity, high capillarity, etc. The only known example is that of liquid helium at temperatures close to absolute zero

---

adjective

1. being or relating to a superfluid

superfluid Scientific  

/ so̅o̅′pər-flo̅o̅′ĭd /

1. A fluid, such as liquid helium, that flows with little or no friction at temperatures close to absolute zero.

---

Other Word Forms

• superfluidity noun

Etymology

Origin of superfluid

First recorded in 1940–45; super- + fluid

Example Sentences

Instead of freezing, it transforms from a normal gas into a superfluid, a rare state of matter that flows without any resistance and displays strange behaviors, including creeping up the sides of containers.

From Science Daily • Feb. 5, 2026

They observed a superfluid, which typically remains in constant motion, suddenly stop moving.

From Science Daily • Feb. 5, 2026

"Observing an insulating phase that melts into a superfluid is unprecedented. This strongly suggests that the low-temperature phase is a highly unusual exciton solid."

From Science Daily • Feb. 5, 2026

Physicists have long wondered what would happen if a superfluid were cooled even further.

From Science Daily • Feb. 5, 2026

In his most noteworthy calculation, he corrected a longstanding theory of superfluid helium established by Lev Landau, winner of a Nobel Prize in Physics.

From New York Times • Mar. 19, 2024