This is the 276th most frequent Italian word.
sicuramente
Certainly; surely; definitely.
Here, 'sicuramente' expresses a high degree of certainty about the speaker's intention to go on vacation.
Sicuramente andrò in vacanza questa estate.
Surely I will go on vacation this summer.
In this context, 'sicuramente' emphasizes the speaker's affirmation that the proposal is interesting.
È sicuramente una proposta interessante da valutare.
It is definitely an interesting proposal to consider.
'Sicuramente' here indicates the speaker's clear commitment to responding to the call, adding assurance.