Squiggle is a 19th-century blend, probably of 'squirm' (or 'squiggle' dialect) and 'wiggle'/'wriggle', imitative of a wavy, twisting motion. The wording preserves that uncertainty: the older history is best read as a cautious account rather than a fully settled chain. The sound-symbolic element is central: the form imitates or evokes the noise, motion, or sensory impression associated with the modern word. In current use it covers a short irregular wavy line or scrawl. The wider family includes derived forms such as squiggly and related words such as wiggle, wriggle, and squiggly.