To burn off energy or weight is to get rid of it by doing exercise.
Examples of use:
1. The children have been indoors all day and I think they need to run around the garden and burn off all that energy.
2. I’m going running every day to burn off the weight I put on while on holiday.
infinitive – burn off
present simple – burn off and burns off
-ing form –burning off
past simple – burnt off
past participle – burnt off
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