a.

1. 打开的
   My door is always open to visitors.

   我的门永远向来访者敞开。

2. 开阔的，空旷的[B]
   In front of us we saw a stretch of open fields.

   眼前是一片开阔的田野。

3. 敞开的，开着的；无顶的
4. 悬而未决的，未定的
   This is still an open question.

   这仍然是一个尚未解决的问题。

5. 营业的，办公的；出入自由的[F]
   Is the store open from 9 to 7?

   那家商店是从上午九点营业到晚上七点吗？

6. （工作、职位）空缺的[F]
   The position is still open.

   那个职位仍空缺着。

7. 公开的，公然的，不隐晦的
   It's an open secret that his firm is going bankrupt.

   他公司即将破产一事已是公开的秘密。

8. 开放的，可以自由参加的[（+to）]
   That's an open society.

   那是一个开放的社会。

9. 【语】（元音、音节）开的
10. 愿意接受的；易招致……的[F][（+to）]
    They are open to temptations.

    他们容易受诱惑。

    I am open to suggestions.

    我愿意接受各种建议。

vt.

1. 开；打开
   I opened the window after I got up.

   我起床后便把窗子打开。

2. 铺开，展开
3. 开始
   The Conference was opened on October 15.

   大会于十月十五日开始。

4. 使开张（营业）
   He opened a grocery store last month.

   上个月他开了一家杂货铺。

5. 使畅通

vi.

1. 开；张开；展开
   The flowers are opening.

   花正在开放。

2. 开始
   The fair opened on March 17.

   交易会于三月十七日开幕。

3. 开业
4. 展现
   A great future opens before them.

   远大的前程展现在他们面前。

n.

1. 户外，野外[the S]
   We spent that night in the open.

   那夜我们在野外度过。

2. 旷野，空地[the S]
3. 【体】公开赛

adj.

1. allowing access, passage, or view; not closed, fastened, or restricted.
2. exposed to the air or to view or attack; not covered or protected:
   an open boat.
   ▸(of land) not covered with buildings or trees.
   ▸ (open to) vulnerable or subject to.
   ▸(of a town or city) officially declared to be undefended, and so immune under international law from bombardment.
3. spread out or unfolded.
   ▸(of a book) with the covers parted and able to be read.
4. admitting customers or visitors; available for business.
   ▸freely available or accessible.
   ▸(of an offer or opportunity) still available.
5. frank and communicative.
   ▸not concealed; manifest.
   ▸welcoming public discussion, criticism, and enquiry:

   open government.
6. (of a matter) not finally settled.
   ▸ (often open to) receptive to new ideas.
   ▸ (open to) admitting of; making possible.
7. Music  (of a string) allowed to vibrate along its whole length.
   ▸(of a pipe) unstopped at each end.
8. Phonetics  (of a vowel) produced with a relatively wide opening of the mouth and the tongue kept low.
   ▸(of a syllable) ending in a vowel.
9. (of an electric circuit) having a break in the conducting path.
10. (of a fabric) loosely knitted or woven.

v.

1. move (a door, window, etc.) so that it is open.
   ▸undo or remove the cover or fastening of.
   ▸ (open on to/into) (of a door, window, etc.) give access to.
2. unfold or be unfolded; spread out.
   ▸part the covers of (a book) to read it.
   ▸(of a prospect) extend into view.
3. make or become open for customers or visitors.
   ▸ceremonially declare (a building, road, etc.) to be completed and ready for use.
4. formally begin or establish.
   ▸ (open up or open fire) begin shooting.
   ▸(of a counsel in a law court) make a preliminary statement in (a case) before calling witnesses.
   ▸Bridge  make (the first bid) in the auction.
5. make available or more widely known.
   ▸ (open out/up) become more communicative or confiding.
6. break the conducting path of (an electric circuit).

n.

1. (the open) outdoors or in the countryside.
   ▸ (usu. in phr. in/into the open) a lack of concealment or secrecy.
2. (Open) a championship or competition with no restrictions on who may compete.
3. an accidental break in the conducting path for an electric current.