surely

surely /ˈʃɚli/ Brit /ˈʃɔːli/ adverb
surely
/ˈʃɚli/ Brit /ˈʃɔːli/
adverb
Britannica Dictionary definition of SURELY
1 
: in a confident way
2 
formal
a  : without a doubt : certainly
b  — used in negative statements to show surprise that something could be true

slowly but surely

— see slowly