The Spanish word 'bolero' comes from combining 'bola' (meaning 'ball') with the suffix '-ero' (meaning 'relating to'). The Spanish 'bola' itself derives from Latin 'bulla', meaning 'bubble' or 'ball'. The word evolved to describe both a type of dance and, colloquially, someone who tells tall tales or lies. The dance meaning likely comes from the circular movements involved, while the 'liar' meaning may relate to someone who 'throws around' stories like balls.

A simpler and more common Spanish word that shares this etymology is 'bola' meaning 'ball'. This direct connection makes sense since a 'bolero' dance involves circular, ball-like movements. Other related words include 'boliche' (bowling), 'bolear' (to throw), and 'bolita' (little ball).

While English borrowed the word 'bolero' directly from Spanish to refer to the dance and a short jacket, there are other English words that share the Latin root 'bulla'. These include 'bull' (in the sense of a papal bull, which originally referred to the seal or bubble-like medallion on the document), 'bulletin' (originally a sealed document), and 'bubble' itself. The connection between these words and the Spanish 'bolero' lies in their shared reference to something round or spherical.