open up phrasal verb ( see also ↑ open )
1 . OPPORTUNITY if opportunities open up, or a new situation opens them up, they become available or possible:
With a microscope, a whole new world of investigation opens up.
open something ↔ up
The new international agreement opens up the possibility of much greater co-operation against terrorism.
2 . LAND open something ↔ up if someone opens up an area of land, they make it easier to reach and ready for development:
The new road will open up 300 acres of prime development land.
3 . DOOR/CONTAINER ETC to open something that is closed, locked, or covered:
Open up, this is the police!
open something ↔ up
He opened up his case and took out a clean sweater.
4 . SHOP/OFFICE ETC
a) if a shop, office etc opens up or is opened up, someone starts it
b) if a shop, office etc opens up at a particular time, it starts business at that time
5 . DISAGREEMENT/DISCUSSION open something ↔ up to start a discussion or argument:
The article was written with the intention of opening up a public debate.
6 . COMPETITION/RACE if someone opens up a lead in a competition or race, they increase the distance or number of points by which they are winning
7 . TALK to stop being shy and say what you really think:
Last night was the first time that Ken had opened up about his feelings.
8 . WITH A GUN to start shooting
9 . HOLE/CRACK ETC if a hole, crack etc opens up or is opened up, it appears and becomes wider