A Gillespie is someone who is significantly older than they actually are, probably look at facebook memes.. A stealth boomer.
Person 1: That 20 year old came over to me and asked me what the new slang is
Person 2: That's not a 20 year old, that's a Gillespie.
Person 2: That's not a 20 year old, that's a Gillespie.
by PegasusP May 02, 2023
When a gang of men from a broadly northern seaside town come to slap a family member known by Gillespie with used gills of a fish and form a fishermen’s pie as tea.
by Thenastyman December 03, 2019