IPA: /ˌdɛtəˈsteɪʃən/
KK: /dɛtəˈsteɪʃən/
A strong feeling of dislike or hatred towards someone or something.
Her detestation for injustice motivated her to become an activist.
Detestation is formed from "de-" (meaning down or away) and "testari" (meaning to witness or testify) combined with the suffix "-ation" (indicating a process or action). The word describes the process of witnessing or feeling strong dislike or hatred, as if one is pushing away from something they cannot bear to witness.
Think of 'pushing away' ('de-') from something you strongly dislike or hate, which is what detestation means.