What does acclimation mean?
Acclimation is the process by which a person, animal, or plant becomes adjusted to a new climate, environment, or set of conditions. The term most often appears in scientific and practical contexts — altitude acclimation among mountaineers, heat acclimation in athletes, or the acclimation of laboratory animals to new surroundings — but it also extends to everyday situations, such as a newcomer's gradual acclimation to a new job or city. The word emphasizes gradual physiological or psychological adaptation rather than instant change, and it carries a neutral, matter-of-fact tone. In American English, 'acclimation' and its verb form 'acclimate' are standard; British English typically favors 'acclimatization' and 'acclimatize'. A useful word precisely because adaptation is so universal, acclimation names a process everyone experiences, whether facing thinner mountain air, a sweltering summer, or simply the first weeks in unfamiliar circumstances.
nounThe process of becoming accustomed to a new climate, environment, or set of conditions. It refers to the physiological or psychological adjustment an organism (or person) undergoes when adapting to changed surroundings.
- Physiological adjustment of an organism to a change in its environment, such as altitude, temperature, or climate.
- More generally, the process of becoming accustomed to any new situation, place, or set of conditions.
"After a week of acclimation, the climbers were ready for the thinner air at base camp."
"New employees typically need a period of acclimation before they feel fully productive in their roles."
"The seedlings showed poor acclimation after being moved abruptly from the greenhouse to the open field."
Rarely used in the plural; the uncountable singular is standard, since acclimation denotes a process rather than countable items.
"The study compared the heat acclimations of athletes trained in different climates."
Swap one letter and you get a completely different word: acclimation is about adjusting to thin air, while acclamation is about applause — confusing them at a mountaintop ceremony could be embarrassing.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acclimation
Acclimation derives from the verb 'acclimate', which was formed in the late 18th century from French 'acclimater', itself built on Latin 'clima' (from Greek 'klima'), meaning 'slope' or 'region', which also gives us the English word 'climate'. The prefix 'a-' (from Latin 'ad-', meaning 'to' or 'toward') conveys movement toward a state of climatic fitness. Cognates include 'acclimatize' and 'acclimatization', which share the same root and remain the preferred forms in British English.
Related word forms
How acclimation is actually used
In British English, 'acclimatization' (and the verb 'acclimatize') is generally preferred over 'acclimation' (and 'acclimate'), which are more common in American English. The word carries a neutral, often scientific register, appearing frequently in biology, medicine, sports science, and discussions of relocation or travel.
Easily confused with acclimation
Acclamation means enthusiastic approval or a loud show of praise (as in electing someone 'by acclamation'), whereas acclimation is the process of adjusting to a new environment.