Tweak has this etymological development: Probably from Old English twiccian ('to pluck, gather'), related to twitch; the sense 'to make small adjustments' is a 20th-century development. Important recorded forms include twiccian (Old English). The wording preserves that uncertainty: the older history is best read as a cautious account rather than a fully settled chain. The semantic development is already visible in the history: an older concrete or specialized use was extended into the modern meaning rather than replaced by a separate origin. In current use it covers to adjust or fine-tune something slightly. The wider family includes derived forms such as tweaker and tweaking and related words such as twitch.