Joule -- a unit of electrical/mechanical/heat energy
A four letter word starting with J is jump or joke.
joule
joust
Joule is a science term. It is a unit of energy.
jamoke
Joule is a unit of energy.
Fuji
JunkJambJustJoinJail
java
Reenact. -J
joyful
junta, jelly, joust