서서히 + change verb: 서서히 좋아져요
gradually, slowly
Example
날씨가 서서히 추워지고 있어요.
The weather is gradually getting colder.
Word parts
서 slow+서 slow
Literally 'slowly, slowly' plus the adverb ending -히.
Good to know
Usually pairs with change verbs like -아/어지다: 서서히 나아지다 'gradually get better.'
Related words