The Spanish verb 'extrañar' (meaning 'to miss someone/something' or 'to find strange') comes from the Latin verb 'extraneare' meaning 'to treat as a stranger.' This Latin verb was derived from 'extraneus' meaning 'external' or 'foreign,' which itself came from 'exterus' meaning 'outside, external.' At the root of this word family is the Latin prefix 'ex-' meaning 'out of' or 'outside.'

The semantic evolution from 'treating as a stranger' to 'missing someone' in Spanish is quite intuitive - when we miss someone, they are outside our presence, separated from us like a stranger. Similarly, the meaning 'to find strange' maintains a direct connection to the original Latin sense of something being foreign or external to our normal experience.

Several common Spanish words share this etymology, including 'extraño' (strange, foreign), 'extranjero' (foreigner, stranger), and 'extraño/a' as a noun meaning 'stranger.' All these words carry the core concept of something or someone being outside the familiar or normal sphere.

English speakers can connect 'extrañar' to several familiar English words that come from the same Latin roots. 'Strange,' 'estrange,' and 'stranger' all derive from Latin 'extraneus.' The word 'exterior' comes from Latin 'exterus.' These English cognates all maintain some connection to the concept of 'otherness' or being outside normal boundaries.