sole
UK: səʊl | US: soʊl
adj. being the only one; single or singular
n. the underside of a foot or shoe
n. a type of flatfish (e.g., Dover sole)
The word "sole" originates from the Latin solus, meaning "alone" or "single." The adjective form (e.g., "the sole reason") directly reflects this meaning. The noun form referring to the underside of a foot/shoe evolved from the idea of being the "single" or foundational surface. The fish name "sole" derives from Latin solea, a type of sandal, due to its flat shape resembling a shoe sole.
She was the sole survivor of the accident.
The soles of his shoes were worn out.
Grilled sole is a delicacy in coastal regions.
As the sole heir, he inherited the entire estate.
Check the sole for any embedded debris before hiking.