Meaning

noun a soldier of the American Revolution who was hanged as a spy by the British; his last words were supposed to have been `I only regret that I have but one life to give for my country' (1755-1776)

noun United States astronomer who discovered that sunspots are associated with strong magnetic fields (1868-1938)

noun prolific United States writer (1822-1909)

originFrom Old English halh (“hollow, nook”).

Etymology from Wiktionary, CC BY-SA 3.0