to make something stronger

The pockets on my jeans are reinforced with double stitching. 我牛仔裤的裤兜缝了两道线，很结实。

If something reinforces an idea or opinion, it provides more proof or support for it and makes it seem true.

The final technical report into the accident reinforces the findings of initial investigations. 对事故作出的最终的技术性报告进一步证实了最初的调查结果。

His behaviour merely reinforced my dislike of him. 他的行为只能使我更讨厌他。

to provide an army with more soldiers or weapons to make it stronger

The garrison is to be reinforced with/by another two battalions of soldiers. 守备部队将得到另外两个营的增援。