Plural of chappy; British slang for young men, fellows, or friends (informal and somewhat dated).
From chappy (informal British term for a fellow or man), which comes from chap + -y (diminutive suffix). Chap itself derives from Old English and Middle Dutch sources meaning 'fellow'.
Chappies is pure British slang from the early 20th century—it sounds quaint now, but it perfectly captures the casual camaraderie of soldiers and schoolboys in Edwardian England before world wars changed everything.
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