IPA: /ˈheɪs.tən.ər/
KK: /ˈhæs.tən.ɚ/
A person or thing that causes something to happen more quickly.
The hastener of the project ensured that all deadlines were met ahead of schedule.
Hastener → It is formed from "hasten" (from Middle English *hastenen*, meaning to move quickly) and "-er" (meaning a person who). The word "hastener" refers to a person who causes or encourages haste or quickness.
Think of someone who makes things happen quickly — that's what a hastener does, as they are a person who encourages speed.