'anorthoclase' originates from Greek elements: the prefix 'an-' meaning 'not' combined with 'orthoclase' (from Greek 'orthos' meaning 'straight' and 'klasis' meaning 'breaking').

'anorthoclase' was coined in modern mineralogy (19th century) by prefixing 'an-' to 'orthoclase' (compare German scientific form 'Anorthoklas' and scientific Latin usages), and was adopted into English mineralogical terminology as 'anorthoclase'.

Initially it denoted 'a feldspar not identical to orthoclase'—specifically feldspars of composition intermediate between orthoclase and albite—and it has retained this technical mineralogical sense.