The Spanish word 'bisabuela' meaning 'great-grandmother' is a compound word formed from two Latin elements. The first part comes from Latin 'bis' meaning 'twice', and the second part is derived from Latin 'avus' meaning 'grandfather', which evolved into Spanish 'abuelo/abuela' through the diminutive form 'aviolus'. The prefix 'bis-' is used to indicate one generation further removed than 'abuelo/abuela', thus making it mean 'great-grandmother' - literally like saying 'twice-grandmother'.

The most obvious related Spanish word is 'abuela' (grandmother), which is simply the feminine form of 'abuelo'. Other common Spanish words using the same 'bis-' prefix include 'bisnieto' (great-grandchild) and 'bisabuelo' (great-grandfather). The prefix 'bis-' maintains its meaning of 'twice' or 'two steps removed' in all these family relationship terms.

While English doesn't use the exact same construction for 'great-grandmother', we can find the Latin 'bis-' prefix in English words like 'bisect' (to cut into two parts), 'biannual' (occurring twice a year), and 'bilateral' (having two sides). The Latin root 'avus' is less common in English, but it appears in academic terms like 'avuncular' (relating to an uncle) which shares this ancestral family terminology root.