de ‧ cid ‧ ed ‧ ly /dɪˈsaɪdədli, dɪˈsaɪdɪdli/ BrE AmE adverb
[ Word Family: noun : ↑ decision , ↑ indecision ; adverb : ↑ decidedly , ↑ decisively ≠ ↑ indecisively ; adjective : ↑ decided ≠ ↑ undecided , ↑ decisive ≠ ↑ indecisive ; verb : ↑ decide ]
1 . [+ adjective/adverb] definitely or in a way that is easily noticed:
Cole’s style is decidedly more formal than the previous manager’s.
2 . British English written in a way that shows that you are very sure about a decision:
‘I’m not going to do it,’ said Margaret decidedly.