Old chap relative, 3 letters
Brit's bud, 3 letters
Brit's mac, 3 letters
Brit's dad, 3 letters
British bub, 3 letters
British buddy, 3 letters
Cockney's Mister, 3 letters
Fellow, in British slang, 3 letters
Informal British address, 3 letters
Informal British term of address, 3 letters
Informal term of address, in Britain, 3 letters
Mate, 3 letters
Sir, in Soho, 3 letters
Soho sir, 3 letters
Term of address, at a pub, 3 letters
British blokes, 4 letters
(British slang) boss, 6 letters