great-un·cle or great uncle 
(grātŭngkəl)
(grātŭngkəl)n.
A brother or brother-in-law of one's grandparent. Also called granduncle.
- perish the thought
- perisperm
- perissodactyl
- peristalsis
- peristaltic
- peristaltically
- peristomal
- peristome
- peristomial
- peristylar
- peristyle
- perithecial
- perithecium
- peritonaeum
- peritoneal
- peritoneal dialysis
- peritoneally
- peritoneum
- peritonitis
- peritrich
- peritrichous
- peritrichously
- perivisceral
- periwig
- periwinkle