Surfing slang. A young or inexperienced surfer; (also) a young person, often one considered a nuisance or troublemaker, who frequents a surfing beach but does not surf.
Origin
1940s (in an earlier sense). Shortened from gremlin; compare -y.
Definition of gremmie in US English:
gremmie
(also gremmy)
nounˈɡrɛmi
Surfing slang. A young or inexperienced surfer; (also) a young person, often one considered a nuisance or troublemaker, who frequents a surfing beach but does not surf.
Origin
1940s (in an earlier sense). Shortened from gremlin; compare -y.