A non-geocacher. Based on "Muggle" from the Harry Potter series, which is a nonmagical person. Usually this term is used after a non geocacher looks puzzled at a geocacher making circles with their GPS receiver, or when a non-geocacher accidentally finds a cache. Geomuggles are mostly harmless.
Short version: Muggle
A lot of geomuggles around the cache in summer - use your stealth abilities