IPA: //hoʊlˈhɑːrtɪd//
KK: /ˈhoʊlˌhɑrtɪd/
Showing complete and sincere commitment or enthusiasm without any hesitation or doubt.
She gave her wholehearted support to the project, believing in its success.
Wholehearted → It is formed from "whole" (from Old English *hal*, meaning complete or uninjured) and "hearted" (from "heart", meaning the organ or metaphorically the center of emotion). The word "wholehearted" means fully committed or sincere, as if one is giving their entire heart to something.
Think of being 'complete' ('whole') and giving your 'heart' to something — that's why wholehearted means being fully committed.