Idiom
dredge up somethingdredge up (something)
1.
to remember something from the past.
He hates it when people dredge up the crimes that happened here 20 years ago.You're not dredging that old idea up again, are you?
Usage notes: often said about something unpleasant
2.
to find something after a lot of looking.
We've finally dredged up enough money to have a proper lab with proper equipment.