Osmol

Part of speech: noun

Definitions

1. A unit of osmotic activity equal to one mole of dissolved particles that contribute to the osmotic pressure of a solution
2. A measure of solute concentration equal to one mole of particles that can exert osmotic pressure in a solution
3. The quantity of dissolved particles, one mole in amount, that determines how much osmotic pressure a solution exerts

Etymology: "Osmol" is a shortened form of "osmole," the unit used in chemistry and medicine to count dissolved particles in a solution. The longer spelling is the one from which it is derived, so the shorter form is best understood as a clipped variant of that same term. The full word "osmole" combines "osmo-," from Greek "osmos" meaning "push" or "impulse," with the suffix "-ole," a clipping of "molecule." The first element refers to osmosis, the process named for that same Greek root, in which water moves across a membrane toward the more concentrated side. The second element points to the molecular count, so an osmole measures how many particles are present, regardless of what they are.