A person who explores caves, either as a hobby or profession; a speleologist or cave enthusiast.
From 'cave' (Old French 'cave') plus the English agent suffix '-er' (one who does); directly means 'one who caves or explores caves.'
Cavers have discovered entire ecosystems in caves that exist nowhere else on Earth—blind fish, eyeless insects—making them accidental explorers of alien worlds beneath our feet.
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