IPA: /ˈhɛliˌski/
KK: /hɛlɪˈski/
To ski on snow that is reached by a helicopter, typically in remote areas with fresh powder snow.
They decided to heliski in the mountains for an unforgettable adventure.
Past: heliskied
Past Participle: heliskied
Heliski is formed from "heli-" (derived from "helicopter", which comes from the Greek "helix" meaning spiral and "pteron" meaning wing) and "ski" (from Old Norse "skíða" meaning a split piece of wood or a ski). The term refers to skiing on snow that is accessed by a helicopter, combining the concepts of helicopter and skiing.
Imagine a helicopter ('heli-') taking you to the top of a mountain so you can ski ('ski') down — that's what heliskiing is all about.