The Spanish verb 'centrar' (meaning 'to center') comes from the Spanish noun 'centro' ('center') combined with the verb-forming suffix '-ar'. The noun 'centro' traces back to Latin 'centrum', which in turn comes from Ancient Greek 'κέντρον' (kentron), meaning 'point, spike, or center'. The Greek word originally referred to a sharp point or prick, and over time its meaning evolved to refer to the center point of a circle, and then more generally to any central point or middle.

The most obvious related Spanish word is 'centro' (center), which is the base noun from which 'centrar' is derived. You might encounter 'centro' in common phrases like 'centro comercial' (shopping center) or 'centro de la ciudad' (city center). Another related word is 'céntrico' (central, downtown), as in 'un hotel céntrico' (a centrally-located hotel).

Several common English words share the same Greek ancestor 'kentron'. The most obvious is 'center', which came to English through Old French from the same Latin word 'centrum'. Other related English words include 'central', 'centralize', and 'concentrate'. The word 'eccentric' also contains this root - it literally means 'out of center' or 'deviating from the center', which explains both its geometric meaning and its more common meaning of 'unusual' or 'unconventional'.