sealyham n a village in southwestern Wales where the Sealyham terrier was first bred n a wire-haired terrier with short legs that was first bred in Sealyham Usage(s) Barberryhill Bootlegger, sealyham, best of the terriers. With fine disdain Jock stood in the ring while a silver-blonde Afghan, a sealyham terrier, an English springer spaniel, a Yorkshire terrier and a boxer competed with him for best . Synonym(s) Sealyham Sealyham terrier