tweak /twiːk/ BrE AmE verb [transitive]
[ Language: Old English ; Origin: twiccian 'to pull out' ]
1 . to suddenly pull or twist something:
She leant forward and tweaked both ends of his moustache.
2 . to make small changes to a machine, vehicle, or system in order to improve the way it works:
Maybe you should tweak a few sentences before you send in the report.
—tweak noun [countable usually singular]