to miss the boat

to miss the boat: to lose an opportunity, to fail i some undertaking

• The precious metals market was looking up several months ago, but unfortunately most investors missed the boat.
• Mr.Vlasic's new business went bankrupt within a short time. He really missed the boat by opening a tanning salon near the beach.

to leave open

to leave open: to delay making a decision on (S)

• In making up the job announcement, the firm decided to leave the salary open until a qualified candidate was found.
• We know that the annual summer camp will be held in August, but let's leave the exact dates open for now.

to lose one's cool

to lose one's cool: to get excited, angry, or flustered

• Despite the boos from some in the audience, the actors on stage never lost their cool.
• Although the group of skiers were in danger from an apparent avalanche, their ski guide never lost his cool.

to line up

to line up: to form a line; to arrange to have, to manage to obtain (S)

• The moviegoers lined up in front of the theater to see the most popular film of the summer.
• Rob is going to schedule the famous author to speak at the convention if he can line her up in time.

to cop out

to cop out: to avoid one's responsibility, to quit

This idiom is an informal version of the second definition to back out .

The noun form copout means an excuse for avoiding responsibility.

• Evelyn had agreed to help us with arrangements for the party, but she copped out at the last minute.
• I can't believe that Cindy offered such an explanation for failing to show up. What a poor copout!

to serve (the / one's) purpose

to serve (the / one's) purpose: to be useful, to suit one's needs or requirements

• I don't have a screwdriver to open this, but I think that a knife will serve the purpose.
• Jane prefers working to studying, so it served her purpose to drop out of school and take that job.

to take one at one's word

to take one at one's word: to accept what one says as true, to believe (also: to take one's word for it)

• You should be careful about taking her at her word. She's been known to say one thing but to do another.
• When he offered to be responsible for the fund raiser, I took his word for it. Now he's saying that he's not available to do it.

to check out

to check out: to pay the bill at a hotel or motel and then leave; to investigate, to examine (S)

• The latest you should check out of the hotel is noon.
• The police received a call from someone claiming to have witnessed a murder. The police sent two detectives to check the call out right away.

to check in

to check in: to register at a hotel or motel; to leave or deposit for transporting or safekeeping (S)

• Courtney arrived in town at mid-day and promptly checked in at the Plaza Hotel.
• There were dozens of people at the airline counters waiting to check their bags in for their flights.

to have to do with

to have to do with: to have some connection with or relationship to

This idiom is often used in the negative, as in the first example.

• Ralph insisted that he had nothing to do with breaking the window.
• What does your suggestion have to do with our problem?