Why does 「やきもち」 mean to be jealous? I've heard this word used quite a few times now, and I'm tired of pretending to understand it. Why does refer to being jealous? Is this a slang word? How do people use this word?

The of can be written in two ways, and .

Assuming you know the former(), can mean to be jealous. So, the word is a play on words that have the same sound. The part, meaning rice cake () is said to come from , in other words originated from the phrase (whether actually originated from or not is unclear though).

Sometimes you will see it written as () and young people often use it. For example:

> <\-- As if spoken by a young female
>
>

However, this word has existed for quite some time, so I wouldn't consider it to be slang.