The Spanish word 'pelito' meaning 'little hair' is formed from two parts: the noun 'pelo' (meaning 'hair') and the diminutive suffix '-ito'. The base word 'pelo' comes from Latin 'pilus', which also meant 'hair'. The diminutive suffix '-ito' is a very common Spanish ending that makes words smaller or more endearing.

The most obvious related Spanish word is 'pelo' meaning 'hair', which is the base word from which 'pelito' is derived. Other common words from the same root include 'peludo' (hairy), 'peluquería' (hair salon), and 'peluca' (wig). All these words share the basic meaning related to hair.

While English doesn't have many common words directly from Latin 'pilus', we do see it in some technical terms. For example, 'depilatory' (a substance used to remove hair) contains this root, as does 'pileous' (relating to hair). The word 'pile' as in 'carpet pile' (the raised fuzzy surface) also comes from this Latin root, though this meaning has diverged quite a bit from the original 'hair' meaning.