The Spanish verb 'alfombrar' (meaning 'to carpet' or 'to cover with a carpet') comes from the Spanish noun 'alfombra' (meaning 'carpet'), which in turn has Arabic origins. It can be traced back to the Arabic word 'alḥanbal', which was formed from the Arabic definite article 'al-' combined with 'ḥanbal' meaning 'carpet' or 'rug'. When this word was borrowed into Spanish, the Arabic 'ḥ' sound changed to 'f', and the 'b' sound was influenced by the preceding 'm' sound, resulting in 'alfombra'. The verb 'alfombrar' was then formed by adding the common Spanish verb suffix '-ar' to 'alfombra'.

The noun 'alfombra' is the simpler and more common Spanish word related to 'alfombrar'. While 'alfombra' is the concrete noun referring to the carpet itself, 'alfombrar' is the action verb meaning 'to carpet' or 'to cover with carpet'. This pattern of forming verbs from nouns by adding '-ar' is common in Spanish, making it easier to understand the relationship between these related words.

Unlike many Spanish-English word pairs, 'alfombrar' and its related noun 'alfombra' don't have any clear etymologically related English words because they come from Arabic rather than the Latin or Greek roots that Spanish and English often share. The English words 'carpet' and 'rug' come from different etymological sources entirely.