'astrolog' originates from Latin, specifically the word 'astrologus', where 'astr-' (from Greek 'astron') meant 'star' and '-logus' (from Greek 'logos') meant 'one who speaks or studies'.

'astrolog' changed from Middle English word 'astrologe' (borrowed from Late Latin 'astrologus') and eventually appeared in modern English as the rare/archaic form 'astrolog'.

Initially, it meant 'one who studies the stars', but over time it evolved into its current meaning of 'a practitioner of astrology' and is now regarded as archaic or rare.