1. Spanish origin: Bonilla is a diminutive form of the Spanish name Bono, meaning "good" or "kind". It was often given as a nickname or surname to someone with a pleasant disposition or good qualities.
2. Italian origin: In some cases, Bonilla may have originated from the Italian surname Bonillo. This name stems from the Latin word "bonus", which also means "good" or "kind". It was common for Italian families to adopt surnames based on positive attributes or characteristics.
3. Portuguese origin: Bonilla can also be found as a Portuguese surname, where it is a variant of the name Bonilha. Bonilha is derived from the Portuguese word "bonita", which means "beautiful" or "pretty".
4. French origin: While less common, Bonilla may occasionally have French roots. It could be derived from the old French word "bon" (meaning "good") combined with the diminutive suffix "-illa".
It's important to note that while these are potential origins of the Bonilla surname, the specific origin in a given case may vary depending on the individual family history and geographical location.