Correct spelling, explanation: an English word stylus is usually associated with some electronic devices. However, stylus is a word with a long history as it derives from Latin in which it also had the form stylus and from a Greek stylos. Initially, the word was used to refer to a part of a flower, but when stylus entered English, in the 19th century, it meant an instrument for writing.

Definition of stylus:
1. noun – a needle that is used in a record player or a kind of a stick used to write on an electronic device.
If you use an old stylus, it can scratch your vinyl records badly so it’s better to change it regularly.
I can’t find my stylus anywhere and I simply forgot how to write on a tablet without it.

Collocations with stylus:
A few commonly used collocations with stylus include: include a stylus pen, come with a stylus, and use the stylus.
You have here everything you need and the set even includes a stylus pen, which may turn out to be really handy.
The latest make of this smartphone comes with a stylus and headphones.
At first, I didn’t know how to use the stylus, but now I’ve got used to it and it really makes my work easier.

Incorrect spelling, explanation: some English learners and even native speakers mistakenly associate stylus with the word still. As a result, a common spelling mistake is to write stylus as stilus, which is wrong. The only correct spelling is stylus.