IPA: /ˌɛksoʊˈθɜrməli/
KK: /ɛkˈsoʊθərməli/
In a way that releases heat during a chemical reaction or process.
The reaction occurred exothermally, causing the temperature of the surrounding area to rise.
Exothermally → It is formed from "exo-" (meaning outside) and "thermē" (meaning heat) and the suffix "-ally" (meaning in a manner). The word "exothermally" describes a process that releases heat to the outside environment.
Think of 'outside' ('exo-') and 'heat' ('thermē') to remember that 'exothermally' refers to a process that releases heat to the outside.