IPA: /ˌdɪsɪnˈfɛsteɪʃən/
KK: /dɪsɪnˈfɛsteɪʃən/
The process of removing pests or vermin from a place.
The disinfestation of the old house was necessary to make it safe for living.
Disinfestation → It is formed from "dis-" (meaning apart or away) and "infestare" (meaning to infest). The word describes the act of removing or getting rid of pests or infestations, effectively sending them away.
Think of 'sending away' ('dis-') something that 'infests' ('infestare') — that's why disinfestation means getting rid of pests.