From the Greek words ἀστήρ (astḗr), meaning "star," and‎ λόγος (lógos), meaning "to reckon" from which we get the suffix -logy meaning "the study of," comes the ancient Greek word ἀστρολόγος (astrológos) or astronomer. In ancient Greek, the ἀστρολόγος (astrológos) were those persons who studied the stars.
The only occurrence of ἀστρολόγος (astrológos) in the Septuagint is found in Isaiah 47:13, "You are wearied with your many consultations; let those who study (ἀστρολόγοι) the heavens stand up and save you, those who gaze at the stars, and at each new moon predict what shall befall you."