The term FIRE FUEL is composed of two words, LOG and LOGS. LOG is a three-letter word meaning a large piece of wood that has been cut into a regular shape and used as fuel for a fire. LOGS is a four-letter word meaning multiple pieces of wood that have been cut into a regular shape and used as fuel for a fire. Fire fuel is an important part of starting and maintaining a fire, and LOGS are one of the most common types of fire fuel.