The Spanish word 'luego' meaning 'then' or 'later' comes from the Latin word 'locus' meaning 'place', specifically from its ablative form 'loco'. This semantic evolution from a word meaning 'place' to one meaning 'then/later' reflects how spatial concepts often develop into temporal ones in many languages. The shift likely occurred as 'in that place' began to be used metaphorically to mean 'at that point' or 'after that' in time, eventually becoming the temporal marker we use today in Spanish.

A common related Spanish word is 'lugar' (place), which also derives from Latin 'locus'. While 'luego' evolved to express time, 'lugar' retained the original spatial meaning. Another related word is 'local' (local), which preserves the idea of something being connected to a specific place.

Several English words share the same Latin root 'locus'. These include 'local', 'locate', 'location', and even the more technical term 'locus' itself, which is used in mathematics and science. All these English words maintain the original spatial meaning of the Latin root, unlike Spanish 'luego' which evolved to express time instead of place.