What does defrost mean?
"Defrost" is a verb meaning either to remove frost or ice from a surface or object — such as a windscreen, freezer, or refrigerator coil — or to allow frozen food to thaw until it is soft enough to cook or eat. It is formed from the prefix "de-", indicating removal, combined with "frost," the thin layer of ice crystals that forms on cold surfaces. The word is firmly rooted in everyday domestic life: people defrost chickens overnight in the refrigerator, defrost windscreens on winter mornings with a heater or scraper, and periodically defrost freezers to clear accumulated ice. It also appears as a setting on microwaves and ovens, where a lower power level gently thaws food without cooking it. Neutral in tone and widely understood across English-speaking regions, "defrost" sits alongside near-synonyms like "thaw" and "de-ice," though each has slightly different typical uses. Its usefulness lies precisely in this everyday ubiquity — few words describe a task performed as routinely in kitchens and cars around the world.
verbTo remove frost or ice from something, or to thaw frozen food so that it becomes ready to cook or eat.
- (of food) to become unfrozen, or to make food unfrozen and ready for use: Leave the meat to defrost in the fridge overnight. / I forgot to defrost the bread.
- to remove frost or ice from a surface such as a windscreen or freezer: The car's fan heater quickly defrosted the windscreen.
"Remember to defrost the chicken overnight in the fridge before cooking it."
"You'll need to let the prawns defrost fully before adding them to the curry."
"The pilot switched on the de-icing system, but the ground crew still had to defrost the wings by hand."
"It took several hours for the old freezer to defrost after we unplugged it."
Your freezer probably has a tiny heating element whose only job is to secretly melt its own ice — that's automatic defrosting at work.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of defrost
The verb "defrost" combines the prefix "de-", from Latin indicating reversal or removal, with "frost," an Old English noun related to Old Norse and other Germanic forms denoting frozen dew or ice. As a compound formation, "defrost" arose in modern English to describe both the physical removal of frost and the thawing of frozen substances, particularly food. Cognates sharing the Germanic root of "frost" include "freeze" (Old English "frēosan") and "thaw" (Old English "þawian"), though these are parallel terms rather than direct derivatives.
How defrost is actually used
"Defrost" is common in everyday household and culinary contexts, especially British English, where it is the standard verb for thawing frozen food. In technical or industrial settings (e.g., aircraft, roads), "de-ice" is often preferred when the removal of solid ice rather than frost or thawing of food is meant. The word carries no strong connotation — it is neutral and practical in tone.
Easily confused with defrost
"Deice" specifically means removing ice (typically from aircraft or roads), while "defrost" more broadly covers removing frost or thawing frozen food.