IPA: //æˈθiːɪstɪkəl//
KK: /æθˈiːstɪkəl/
Describing a belief system that denies the existence of any gods or deities.
His atheistical views often led to deep discussions about the nature of belief.
Atheistical → It is formed from "a-" (meaning without) and "theos" (meaning god) and the suffix "-ical" (meaning pertaining to). The word describes a state or quality of being without belief in gods or deities.
Think of 'without' ('a-') and 'god' ('theos') to remember that 'atheistical' refers to a belief system that does not include gods.