IPA: /ɪnˈkrɛdəbli/
KK: /ɪnˈkrɛdəbli/
To a very high degree; extremely or surprisingly.
She was incredibly talented at playing the piano.
Incredibly → It is formed from "in-" (meaning not) and "credere" (meaning to believe) combined with the suffix "-ible" (meaning capable of being). The word "incredibly" means not capable of being believed, often used to describe something astonishing or extraordinary.
Think of something that is 'not believable' ('in-') because it is so astonishing or extraordinary.