Meaning:

opposite; contrary; turn over; return

Origin:

骨文中，“反”字像一只手正向着崖边攀登，是“攀”的本字，后来本义消失，意思变为“相反”、“反叛”。
On ancient oracle bone inscriptions, “反” looks like a hand climbing cliff, making it the original character of “攀” (to climb). Then, its original meaning disappeared, changing to “opposite” or “rebel.”

Words：

   反思   (fǎnsī)       : reflection

   反常  (fǎncháng) : abnormal

   相反  (xiàngfǎn)  : contrary

   反馈  (fǎnkuì)     : feedback

   反复  (fǎnfù)       : repeatedly

Examples:

1. 这次采访为什么失败了，咱们应该好好反思一下儿。

    Zhècì cǎifǎng wéishén me shībài le, zánmen yīnggāi hǎo hǎo fǎnsī yī xiàr.

    As to why this interview failed, we should reflect.

2. 我们在等待用户对这款新产品的反馈。

    Wǒmen zài děngdài yònghù duì zhè kuǎn xīn chǎnpǐn de fǎnkuì

    We are waiting for users’ feedback on this new product.