K1
K1 is a designation that appears across several domains.
In vitamins, K1 (phylloquinone) is the form found in leafy greens, essential for blood clotting.
In sports, K-1 is a major kickboxing promotion and ruleset originating in Japan.
K1 also designates visa categories, mountain peaks, and racing classes—the number typically indicating first or primary in a series.
Hard to accomplish
- demandingRequiring great effort
- arduousDemanding strenuous effort
- gruelingExtremely tiring and demanding
- strenuousRequiring intense exertion
daunting · formidable · taxing · rigorous · punishing · treacherous · technical · exposed
challenging
Hard to accomplish
- demandingRequiring great effort
- arduousDemanding strenuous effort
- gruelingExtremely tiring and demanding
strenuous · daunting · formidable · taxing · rigorous · punishing · treacherous · technical · exposed · vertical
summit
Peak or diplomatic gathering
crevasse · glacier · altitude · expedition · mountaineer · basecamp · crampons · icefall · avalanche · ropes
frigid
Extremely and intensely cold
hypothermia · snowpack · windchill · blizzard · subzero · exposure · layering · insulation · down · fleece
Legal mandate requiring departure
visa denial · citizenship · immigration ban · green card · undocumented status
Ground-based submission wrestling
wrestling · grappling · judo · MMA · Greco-Roman wrestling