IPA: /prɪˈvɛn.tə.tɪv/
KK: /prɪˈvɛntətɪv/
Intended to stop something from happening or to reduce the risk of something occurring.
Regular exercise is a preventative measure against many health issues.
Preventative → It is formed from "pre-" (meaning before) and "venire" (meaning to come). The word "preventative" refers to something that comes before to stop or hinder an event from occurring.
Think of something that acts 'before' ('pre-') to 'come' ('venire') and stop an event from happening — that's what preventative means.