솔직히 말하면 (to be honest); 솔직히 + opinion
honestly, frankly
Example
솔직히 말하면 그 영화는 별로였어요.
To be honest, that movie wasn't great.
Word parts
솔 frank+직 straight
Literally 'frank and straight'.
Good to know
Pronounced [솔찌키]; 솔직히 말하면 is a very common opener for an honest opinion.