'autocollimator' originates from Greek and Latin/French components: specifically 'auto-' from Greek 'autos' where 'autos' meant 'self', and 'collimator' from Latin/French (via Latin/French 'collimare'/'collimateur') where the root related to directing or making parallel (as in 'collimate').

'autocollimator' formed in modern English as a compound of 'auto-' + 'collimator' during the 20th century as optical instrumentation developed; 'collimator' itself came into English via French 'collimateur' from Latin-rooted terms and earlier technical use in optics.

Initially, components like 'collimate' referred to producing or checking parallel rays; over time the compound 'autocollimator' came to mean a specific instrument that uses reflected beams for precise angular measurement and alignment.