From Longman Dictionary of Contemporary Englishtweaktweak /twiːk/ verb [transitive] 1 PULLto suddenly pull or twist something She leant forward and tweaked both ends of his moustache.2 IMPROVEto 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]→ See Verb table
Examples from the Corpus
tweak• To make sure, it goes round corners rather than through the hedge, its chassis has been tweaked by Lotus.• Then you have to tweak, evaluate, and see what works.• Matthew tweaked her nose and laughed.• He lay in bed and relished the pleasure of happiness, tweaking his fingers and toes with joy.• Henry leaned forward and tweaked my ear playfully.• She tweaked Thérèse's earlobe: slow down!• Perhaps you should tweak that line or paragraph that throws the structure off.• He had tutted and twitched and tweaked, then proceeded to do more for her than she had thought possible.Origin tweak Old English twiccian “to pull out” 