means to a great extent, very much, or to an extent that... [blah-blah]. Therefore, for the latter meaning, you'd use the word to emphasize that things happened beyond what you were expecting.
Another dialect word that carries the same meaning is zvekuti and that's what you will often hear the most in everyday Shona or Shonglish conversation because don't too many people use the word zvokuti like that.
I think I am done with the expagoration so it's time for some examples and here we... go:
Ndakanakigwa nebhaisikopo iro zvokuti.
I enjoyed that movie to a great extent.
I love her (or him) very much.
Ndakanga ndine nzara, ndakadya pitsa yose ndega zvekuti handina kukwanisa kubva pasofa rangu kwehusiku hwose nekuzvimbirwa.
I was so hungry, I ate the entire pizza by myself to an extent that I couldn't move from my couch for the rest of the night because my stomach was full.