IPA: /əˈstrɒlədʒər/
KK: /əˈstrɒlədʒər/
A person who studies the positions and movements of stars and planets to predict events in people's lives.
The astrologer provided insights about my future based on my birth chart.
Astrologer is formed from "astro-" (from Greek "astron", meaning star) and "-loger" (from Greek "logia", meaning study or discourse). An astrologer is someone who studies the stars and their influence on human affairs.
Think of someone who studies the 'stars' ('astro-') and engages in 'discourse' or 'study' ('-loger') about them — that's what an astrologer does.