A-Frame Tent: An older style of tent, usually with a ridge pole running the length of the tent for support, from which the tent walls drape forming an A shape when viewed from the tent ends.
Acetal: A crystalline thermoplastic polymer material. Acetal characteristically has excellent tensile strength, stiffness, surface hardness and chemical resistance. Acetal has excellent flexural memory and property retention when subjected to repeated loading. Acetal is recommended for high performance applications. Physical properties remain consistent across a wide range of temperature, relative humidity, and weather conditions.
Actiwool: Actiwool is boiled wool, wind resistant and highly breathable.
Active Cut: This is a fit of a particular item of outdoor sports clothing that has been designed to minimise the restriction on your body moving freely. This is naturally most important for people involved in aerobic outdoor sports but is sometimes chosen for reasons of comfort and style.
Adjustable Cuffs - Jackets: A hook/loop/velcro tab that allows rapid cuff closure and adjustment, even when wearing bulky mitts. The elasticated cuff reduces heat loss without impeding circulation at the wrist. To ventilate the sleeve, open the cuff to its fullest extent and secure using the secondary hook/loop strip.
Adze: The flat cutting end of an ice axe head.
Airmesh: Airmesh provides great ventilation in a variety of products including bags, shoes and jackets. This helps avoid the build-up of unwanted moisture and heat against the skin or clothes.
Altimeter: An instrument that measures elevation by using barometric (air) pressure.
Anti-Compression Pads - sleeping bags: Anti-Compression Pads include thin strips of Polarguard 3D in high pressure areas. These provide essential support and warmth and improve thermal efficiency by an astounding 13%.
Anti Microbial Finish: A treatment that inhibits bacteria and mold growth that among other things stops clothes smelling.
Articulated: Normally associated with the cut of a garment to suggest it has been shaped or curved to fit the natural shape of the body. This reduces the amount of material around joints making the garments feel less restrictive.
Ascenders: Devices (e.g. Jumars) used to ascend a rope.