The Spanish verb 'bajar' (meaning 'to lower' or 'to go down') comes from the Latin word 'bassus', which meant 'short and stout'. This evolved into the Vulgar Latin verb 'bassiare' meaning 'to lower'. The connection between 'short' and 'low' is quite intuitive - something that is short in height is naturally lower to the ground.

A closely related and simpler Spanish word is the adjective 'bajo', meaning 'low'. 'Bajo' comes directly from the same Latin root 'bassus', and 'bajar' is essentially the verb form meaning 'to make something low' or 'to lower'. You'll often see 'bajo' in common phrases like 'voz baja' (low voice) or 'piso bajo' (ground floor).

While English 'base' and 'bass' (as in bass note in music) are related to Spanish 'bajar' and 'bajo', coming from the same Latin root 'bassus'. The English word 'base' refers to the bottom or lowest part of something, while 'bass' in music refers to the lowest range of notes - both maintaining that original connection to 'lowness'.