mercadillo
flea market
merchant
trader
+
-illo
diminutive suffix
Mercadillo means flea market and can be thought of as merchant0 + -illo1 (diminutive1), suggesting a smaller or more informal place where merchants sell goods.
noun
- flea marketA small market or street fair, often selling second-hand goodsCompré esta antigüedad en el mercadillo local. // I bought this antique at the local flea market.