n. 一种硬件设备（用于加在计算机上以扩展其功能）；追加
英文词源
add-on (n.)
"additional component," 1941, from add (v.) + on.
双语例句
1. Remove from the heat, add the parsley, toss and serve at once.
端离炉子，加上欧芹，颠起翻面后就立刻上桌。
2. His comments are bound to add fuel to the debate.
他的话必将为争论推波助澜。
3. Add a few drops to half a tumbler of water.
在半玻璃杯水里面加上几滴。
4. Columns are usually intended in architecture to add grandeur and status.
圆柱在建筑中通常用来增添气势和显示地位。
5. Add up all the income you've received over the period in question.
把那个时期里你拿到的所有收入加在一起。
