Utterly means completely or entirely, with no exceptions or doubts.
When people say something is utterly amazing, they mean it's really impressive and can't be improved. You might hear someone describe a view as "utterly breathtaking" - that means it takes your breath away because it's so beautiful. Utterly often also implies strong feelings like love, excitement, or surprise. For example, if you're completely in love with someone, they could be the one who has utterly captured your heart.
Completely, entirely, to the fullest extent
Example: I have failed you utterly.
