'subdivide' originates from Latin elements: the prefix 'sub-' and the verb 'divide' from Latin 'dividere', where 'sub-' meant 'under, below' and 'dividere' meant 'to separate, divide'.

'subdivide' formed by adding the Latin prefix 'sub-' to the verb 'divide' (from Latin 'dividere'), which passed into Old French and Middle English (e.g. Middle English 'dividen') before becoming the modern English 'divide' and later 'subdivide'.

Initially the root meant 'to separate or part', and with the prefix 'sub-' the compound came to mean specifically 'to divide into smaller parts'; this core idea has been preserved in modern usage.