1. the act of running an engine slowly without being in gear
2. the act of spending time without working or being productive

1. running slowly without being in gear or without doing useful work
Usage: present participle of idle
2. spending time doing nothing productive
Usage: present participle of idle

Examples

• The car was idling in the driveway while she ran inside.
• Stop idling and get back to work.
• He spent the afternoon idling by the pool.
• The truck’s idling created exhaust fumes.
• She was idling away her summer vacation.
• The engine’s idling sound was barely audible.
• Too much idling wastes fuel.