What does deliquescent mean?
Deliquescent is an adjective describing something that becomes liquid, most commonly by drawing moisture out of the surrounding air. In chemistry, a deliquescent substance—such as calcium chloride, potassium hydroxide, or certain salts—absorbs water vapor from the atmosphere until it dissolves in that absorbed water and forms a concentrated solution, often turning from dry crystals into a wet puddle over time. The word also has a broader, more literary sense, applied to anything softening or melting away, such as wax in heat or fruit gone overripe. Because of its technical roots, deliquescent belongs mainly to scientific writing, where it contrasts with hygroscopic (which merely attracts moisture without necessarily liquefying) and with desiccant materials designed to stay dry. Its Latin ancestry, meaning literally 'melting away,' gives it a precise, elegant quality that makes it valuable wherever exact description of this transformation matters.
adjectiveTending to become liquid, especially by absorbing moisture from the air. In chemistry, describing a substance that dissolves in and absorbs atmospheric water vapor until it forms a solution.
- (Chemistry) Tending to absorb moisture from the air until dissolving into a liquid solution.
- (General/literary) Becoming or liable to become liquid; melting away.
"The calcium chloride pellets had turned deliquescent after weeks in the humid storeroom, pooling into a clear brine."
"Potassium hydroxide is so deliquescent that an open container will soon fill with its own concentrated solution."
"In the summer heat, the old candle stubs lay deliquescent along the windowsill."
Leave the wrong salt on your shelf during humid weather and it will literally drink the air until it melts into a puddle — that's deliquescence at work.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does deliquescent come from?
Deliquescent derives from the Latin verb deliquescere, formed from de- ('away, down') and liquescere ('to melt, become liquid'), itself rooted in liquere, 'to be fluid' — the same root behind English words like liquid and liquor. The term entered English in the late eighteenth century through scientific writing, as chemists needed a precise label for solids that dissolve in absorbed atmospheric moisture. Related English forms include the verb deliquesce and the noun deliquescence.
Related word forms
How deliquescent is actually used
Primarily a technical term used in chemistry, pharmacy, and materials science; outside those fields it appears mostly in literary or figurative writing about things melting or softening. It carries a neutral-to-learned register and is not common in everyday speech.
Easily confused with deliquescent
A desiccant absorbs and removes moisture to stay dry, whereas a deliquescent substance absorbs moisture until it dissolves into a liquid.
Effervescent describes bubbling or fizzing as gas escapes, while deliquescent describes a solid turning to liquid by absorbing water.