Give it some welly
Definition 1 of 1
Pro Tip 1/3British Origin
Remember, this phrase is British slang and may not be understood outside the UK. 
When I studied abroad, nobody understood when I said to 'give it some welly' during soccer practice.
Pro Tip 2/3Informal Usage
'Give it some welly' is casual, so it's not for formal contexts like business meetings or academic papers. 
At the team-building event, the leader encouraged everyone to 'give it some welly' in the tug-of-war.
Pro Tip 3/3Motivational Context
Use it to inspire or motivate someone to put in more effort or energy. 
Come on, you can solve this puzzle if you just 'give it some welly'!