jolt just jump
A four letter word that starts with J and ends with M: jism.
jest
Jeer
Juno
Janitor is a sanitation word. It begins with the letter j.
Some four letter J words are:jackjadejailJakejapejazzjeerjerkjestjiltJilljinxjivejoeyjohnjoinjokejoshjudojumpjunkjuryjustjute
The word jiff is the only four letter English word that starts with J and ends with F. It's an 'informal' word, a shortened form of jiffy.I'll be there in a jiff.
jury, joey (baby kangaroo), July
"Jardin" is a French word that starts with the letter J. It means "garden" in English.
jester
jaguar
jenga