IPA: /ˌɪrɪˈzɪstəblɪ/
KK: /ˌɪrɪˈzɪstəblɪ/
In a way that is too attractive or appealing to be resisted or avoided.
The dessert looked so delicious that I found it irresistibly tempting.
Irresistibly → It is formed from "in-" (meaning not) and "resistere" (meaning to resist) combined with the suffix "-ibly" (meaning in a manner). The word "irresistibly" means in a manner that cannot be resisted or opposed.
Think of something that cannot be "resisted" ('resistere') — the 'in-' means not, so 'irresistibly' describes something that is impossible to resist.