i ‧ ci ‧ ly /ˈaɪsəli, ˈaɪsɪli/ BrE AmE adverb
[ Word Family: verb : ↑ ice , ↑ de-ice ; noun : ↑ ice , ↑ icicle ; adjective : ↑ icy , ↑ iced ; adverb : ↑ icily ]
if you say something icily, or look at someone icily, you do it in an angry or very unfriendly way:
‘I want you to leave now,’ she said icily.