causal

The word 'causal' is a direct inheritance from the Late Latin term 'causalis', meaning 'relating to a cause'. Its core morpheme, 'caus-', originates from the Latin noun 'causa', which carried the primary senses of 'reason', 'motive', and 'legal case'. This Latin root is thought to be of uncertain deeper origin, though some connect it to a Proto-Indo-European root meaning 'to strike' or 'to cut', metaphorically evolving into the concept of 'that which brings about an effect'. The suffix '-al', also from Latin, is a prolific formative in English that converts nouns into adjectives. Thus, the literal construction 'of or relating to a cause' has remained semantically stable, precisely describing the connection between an event and its effect.

Structure: caus (cause) + al (adjective suffix) caus (from Latin 'causa', meaning 'cause, reason, case'); al (from Latin '-alis', an adjectival suffix meaning 'of, relating to').