fear ‧ ful ‧ ly /ˈfɪəf ə li $ ˈfɪr-/ BrE AmE adverb
[ Word Family: noun : ↑ fear , ↑ fearfulness ≠ ↑ fearlessness ; adjective : ↑ fearful ≠ ↑ fearless , ↑ fearsome ; verb : ↑ fear ; adverb : ↑ fearfully ≠ ↑ fearlessly ]
1 . in a way that shows you are afraid:
She glanced fearfully over her shoulder.
2 . [+ adjective/adverb] British English old-fashioned extremely:
She’s fearfully clever.