osmotic pressure

American  

noun

Physical Chemistry.

1. the force that a dissolved substance exerts on a semipermeable membrane, through which it cannot penetrate, when separated by it from pure solvent.

---

osmotic pressure British  

noun

1. the pressure necessary to prevent osmosis into a given solution when the solution is separated from the pure solvent by a semipermeable membrane

---

Etymology

Origin of osmotic pressure

First recorded in 1885–90

Compare meaning

How does osmotic-pressure compare to similar and commonly confused words? Explore the most common comparisons:

• hydrostatic vs. osmotic pressure

Example Sentences

Calculations based on osmotic pressure suggest that foam would need to be about a meter tall before liquid begins to drain.

From Science Daily • Mar. 23, 2026

They also calculated an "effective osmotic pressure" for this process, which turned out to be much lower than predictions based on bubble size and surface tension alone.

From Science Daily • Mar. 23, 2026

The cells in our body have a signaling system that responds to various external stimuli such as antibiotics and osmotic pressure changes.

From Science Daily • Jan. 17, 2024

Convert the osmotic pressure to atmospheres, then determine the molar concentration from the osmotic pressure.

From Textbooks • Feb. 14, 2019

The circulation of the sap in plants and trees is also in great part due to osmotic pressure.

From The Mechanism of Life by Leduc, Stéphane