What does acclimatation mean?
Acclimatation is a noun denoting the process by which a person, animal, or plant becomes accustomed to a new climate or unfamiliar environmental conditions. It covers both the gradual physiological adjustments the body makes — such as changes in breathing, metabolism, or temperature regulation — and the broader settling-in that follows a move to a different environment. The word carries a neutral, scientific tone and appears most often in technical, medical, or travel-related contexts. In contemporary English it is rare: most writers prefer acclimatization, or the shorter American variant acclimation, and acclimatation now lingers chiefly in older texts and in translations from French, where it remains the ordinary word for the same concept. Understanding acclimatation is useful for readers of nineteenth- and early twentieth-century scientific literature, where it was the term of choice for describing how organisms adapt over time to heat, cold, altitude, or humidity.
nounThe process of becoming accustomed to a new climate or to new conditions; an older and now rare synonym of acclimatization.
- The process of adapting physiologically or psychologically to a new climate or set of environmental conditions.
"After months of careful acclimatation, the explorers were finally able to work at full strength in the thin mountain air."
"The botanists allowed two weeks for the seedlings' acclimatation before transplanting them outdoors."
"His rapid acclimatation to the desert heat impressed the rest of the expedition."
Rarely used in the plural; when needed, it follows the standard pattern for nouns ending in -tion.
"The study compared the acclimatations of lowland and highland populations."
Before 'acclimatization' won the spelling war, English speakers once reached for 'acclimatation' — a word borrowed almost straight from French that has quietly faded into the dictionary's margins.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acclimatation
Acclimatation derives from the French acclimatation, itself formed from climat (climate) with the prefix ac- indicating movement toward a state, on the model of Latin-derived forms in -atio. The word entered English in the nineteenth century alongside growing scientific interest in how plants, animals, and people adjust to new climates. Its more successful English rival, acclimatization, eventually displaced it, leaving acclimatation as a largely historical variant that still reflects its close kinship with the French vocabulary of natural history.
How acclimatation is actually used
Acclimatation is markedly less common than acclimatization (or the shorter American form acclimation) and may strike modern readers as archaic or as a Gallicism. It survives mainly in older scientific writing and in translations from French, where acclimatation remains the standard term.
Easily confused with acclimatation
Acclimatization is the standard modern English term for adjusting to a new climate or conditions, while acclimatation is a rarer, largely historical variant of the same meaning.
Acclamation means enthusiastic approval or applause, especially by voice vote, whereas acclimatation refers to physiological adjustment to new conditions.