1. the process of becoming adjusted to a new climate or environment
Usage: British spelling; American English uses 'acclimatization'; commonly used in biology, ecology, and environmental contexts
2. the physiological or behavioral changes an organism undergoes to survive in a new environment
Usage: technical usage in biology and physiology

Examples

• The mountaineers spent two weeks at base camp for acclimatisation before attempting the summit.
• Plants require a period of acclimatisation when moved from a greenhouse to outdoor conditions.
• The acclimatisation of Arctic animals to warmer temperatures is a concern for climate scientists.
• Acclimatisation to high altitude involves increased red blood cell production.
• Immigrants often experience a gradual acclimatisation to their new country's culture and weather.
• The zoo provided a special acclimatisation period for the newly arrived animals.
• Acclimatisation to cold water can improve a swimmer's performance in winter competitions.