n.

1. 平头钉，大头钉；图钉[C]
   Joe hammered a tack into the wall to hang a picture.

   乔用锤子把一只大头钉敲进墙中用来挂一幅画。

2. 粗缝针脚；假缝[C]
3. 【船】（帆的）上下脚；上下角索[C]
4. 【海】（帆船的）航向[C]
5. 行动步骤，方针[U][C]
   If you can't persuade him, try a new tack.

   如果你不能劝服他，那就试试新的方法吧。

6. 粘性，粘着力[U]

vt.

1. 用平头钉钉[（+down）]
   We tacked some posters on the wall.

   我们把一些海报钉在墙上。

2. 暂时用粗针脚缝
3. 附加，增补[（+to/on/onto）]
   They've tacked a couple of new clauses on to the end of the contract.

   他们在合同的末尾加了两条新的条款。

4. 使（船）抢风转变航向

vi.

1. 抢风转变航向
   The sailing ship was tacking.

   帆船一路换抢航行。

2. 改弦易辙，改变方针

n.

1. a small, sharp broad-headed nail.
   ▸N. Amer. a drawing pin.
2. a long stitch used to fasten fabrics together temporarily, prior to permanent sewing.
3. a course of action:
   there is no reason for them to change tack now.
4. Sailing  an act of tacking.
   ▸a boat's course relative to the direction of the wind.
5. Sailing  a rope for securing the corner of certain sails.
   ▸the corner to which such a rope is fastened.
6. the quality of being sticky.

v.

1. fasten or fix with tacks or with temporary long stitches.
2. (tack something on) add something to something already existing.
3. Sailing  change course by turning a boat's head into and through the wind.
   ▸make a series of such changes of course.

n.

n.