Crop up

Definitions

to happen unexpectedly or suddenly
Typically used to describe an unforeseen event or situation that arises without warning or prior expectation
to appear or become noticeable
Often used to refer to something that becomes apparent or evident, especially after being hidden or unnoticed
to mention or bring up
Can be used to indicate the act of mentioning or bringing up a topic or issue in conversation

Examples of Crop up

The topic of climate change has cropped up in several debates lately.

This idiom is used when someone or something appears unexpectedly. In this example, the topic of climate change hasn't been discussed much earlier, but suddenly it has become a topic of discussion during debates.
I found out that my friend has been promoted at work. It just cropped up in our conversation.

This idiom is used when someone mentions something unexpectedly during a conversation. In this example, the friend did not notify the speaker earlier about the promotion, but suddenly brought it up during the conversation.
The problem cropped up again during the software's testing phase.

This idiom is used when a problem that was previously solved or fixed, appears again unexpectedly. In this example, the problem was supposed to be fixed earlier, but it resurfaced during the testing phase of the software.
The police found the missing person's cell phone near the lake. It just cropped up during their search.

This idiom is used when something is discovered unexpectedly during a search or investigation. In this example, the phone was not found earlier, but during the police search near the lake, it was discovered.
The unexpected news about the company merger cropped up during the team meeting.

In this context, "crop up" means "appear suddenly" or "become known unexpectedly." Here, the news about the merger was not previously discussed or announced, but rather revealed during the team meeting.
My grandfather's old watch cropped up in a garage sale last weekend. I couldn't believe my luck!

This example uses "crop up" to mean "appear unexpectedly" once again, but this time in reference to a physical object. The speaker found their grandfather's old watch at a garage sale, which they hadn't seen in a long time.
I hope my lucky socks crop up soon, as I've been having a terrible string of bad luck lately.

Here, "crop up" is being used more metaphorically. The speaker is talking about a superstition they have - that wearing a certain pair of socks brings them good luck. They're hoping that these socks will reappear soon, as they've been experiencing a string of bad luck.
As I was cleaning out my closet, an old hoodie cropped up that I'd forgotten about. It's so comfortable!

This example uses "crop up" to mean "reappear" or "become visible again." The speaker found an old hoodie in their closet that they'd forgotten about due to lack of use. They were reminded of its existence when they found it while organizing their closet.

Conclusion

The idiom "crop up" can have a few different meanings, but they all revolve around something unexpected or sudden. Whether it's an event, situation, or topic being mentioned, the phrase conveys a sense of surprise or unexpectedness. It can also imply that something was previously hidden or unnoticed, and has now become noticeable.

Origin of "Crop up"

The origin of this idiom is uncertain, but it is believed to have come from the agricultural practice of growing crops. In farming, crops can often "crop up" unexpectedly, as they grow and sprout in unexpected places. This idea of something appearing unexpectedly may have been transferred to the figurative use of the phrase.

Another possible origin could be related to hunting, where prey can suddenly "crop up" or appear out of nowhere. This sense of something appearing suddenly and unexpectedly may have also influenced the use of the phrase.

Overall, the idiom "crop up" has been in use since at least the late 18th century, and its exact origins may be difficult to trace. But its meaning has remained consistent, conveying a sense of something unexpected or sudden.