To adjust or modify something slightly to improve it, or a small adjustment or modification.
Probably from Old English twiccian 'to pluck, pull sharply', related to 'twitch'. The modern sense of 'fine-tune' emerged in the mid-20th century, popularized in technical and creative contexts.
In tech culture, 'tweaking' has become almost an art form - the careful optimization of systems for better performance. The word perfectly captures the delicate nature of improvement: too heavy-handed and you break things, but just the right touch can make everything work beautifully.
Complete word intelligence in one call. Free tier — 50 lookups/day.