퍽이나 + adjective; sarcastic: 퍽이나 그러겠다
very, quite; (sarcastic) sure, as if
Example
다들 우는 걸 보니 시험이 퍽이나 어려웠나 봐요.
Seeing everyone cry, the exam must have been really hard.
Word parts
퍽 'very' + emphatic -이나.
Good to know
In casual speech it's often sarcastic: 퍽이나 잘도 하겠다 'Yeah, as if you'd do it.'
Related words