"Horny" is English and means "horny".
Horny comes from the English and means as much as horny. In contrast to the German "geil", which is also used, among other things, to express that something is particularly "great", the English horny is directly equated with sex and the desire for it. Anyone who claims to be "horny" is looking for a partner to fuck.
In common usage, the word is perceived as rather "obscene". Therefore, it is self-explanatory why horny is also used in the context of Dirty Talk plays an important role. Many couples thus get themselves going.
And yet: even though this term is still considered obscene by many, "horny" (just like "horny") has managed to be included more and more in everyday language - especially among young people. Today, there are not only many songs, but also clothing labels and similar sectors that love to shock with this word and polarise accordingly.
Some gays also use the term in chats to draw the other person out a little. After all, it is a short, quickly written, but all the more meaningful word, with the help of which the other person knows directly in which direction the conversation is being steered or could be steered.
Often a short "Horny?" greeting is enough to start a horny sex chat or maybe even a subsequent real date.