Green’s Dictionary of Slang

the testicles.

1653		Urquhart (trans.) Gargantua and Pantagruel (1927) I Bk II 322: The fire which I had cast into the lap of my poultry roaster burned all his groin, and was beginning to seize upon his cullions.
1661		G. Rogers Horn Exalted 8: In our brain theres a belchose and cogliones lying lovingly close together.
2002		(con. WWII) R. Mooney Father of the Man Prologue: ‘Balls,’ Conklin explained, ‘sometimes referred to as nuts, gonads, stones, rocks, cods, cullions, bollocks, family jewels, or – for the learned among us – testicles or testes.’.