plunge pool 
noun
1A deep basin excavated at the foot of a waterfall by the action of the falling water.It reminded Callan of a booming waterfall as it crashes into the plunge pool below....
- For almost two decades, the Tarahumara frog has been absent from the southern Arizona canyons and deep plunge pools to which it had adapted over millennia.
- Spectacular waterfalls tumble into convenient plunge pools for the refreshment of weary walkers.
2A small, deep swimming pool, typically one filled with cold water and used to refresh or invigorate the body after a sauna.The hotel has an outdoor swimming pool and an indoor plunge pool, and there's also a small fitness centre with a sauna and steam bath, and services on offer range from massage and aromatherapy to hairdressing....
- What's more, as I took my walk of shame, naked women started leaping from saunas into icy plunge pools.
- It all adds up to a spa experience involving several steam rooms, saunas, plunge pools and foot baths, plus a range of innovative treatments.
- metabolomic
- metabolomics
- metabolon
- metabolous
- metaboly
- metaborate
- metaboric acid
- metabotropic
- metabranchial
- metacarpal
- metacarpophalangeal
- metacarpus
- metacenter
- metacentre
- metacentric
- metacercaria
- metacercarial
- metacharacter
- metachemistry
- metachromasia
- metachromatic
- metachromatic leukodystrophy
- metachromatism
- metachrome
- metachromism