The Spanish word 'búho' (meaning 'owl') comes from Vulgar Latin 'bufo', which in turn derives from Classical Latin 'bubo'. Both Latin words also meant 'owl'. The word underwent a relatively straightforward phonetic evolution, with the Latin 'b' sound remaining stable while the internal consonant shifted from 'b' to 'f' in Vulgar Latin, and then to 'h' in Spanish, following common sound change patterns in Spanish phonological development.

While 'búho' itself is a relatively simple and common Spanish word for 'owl', there aren't many commonly used Spanish words that share its specific Latin root. However, you might encounter 'buhar' (to hoot like an owl) or the diminutive form 'buhíto' (little owl), both of which are directly related to 'búho'.

The English word 'bubo' (meaning a swollen lymph node, particularly in reference to bubonic plague) comes from the same Latin root 'bubo', though it took on a different meaning. This semantic shift occurred because swollen lymph nodes were thought to resemble an owl's round face. The scientific name for horned owls, 'Bubo', also directly preserves the original Latin word.