Word for unused in a while?

Question

I'm looking for a word which can fit the gap in the sentence:

"My french is a little bit ______ since I haven't used it in a while"

I came up with poor but hopefully there's a more appropriate word.

Answer 1

Make no mistake about it, by far the most idiomatic way to say that is with the word rusty:

(of knowledge or a skill) impaired by lack of recent practice

Something that's rusty has been affected by rust. This is just like a piece of metal that has been lying around your backyard unused for a long time. And what happens to metal when it's under constant exposure to the atmosphere? It gets covered with rust. The same thing can happen to your language skills if you haven't been practicing them for a while—they might get rusty.

Examples:

My French is a little bit rusty since I haven't been using it for a while.

My Spanish is a bit rusty these days because where I live there is nobody to practice speaking it with.

Answer 2

The word commonly used in BrE is "rusty" because the steel tool you don't use becomes rusty.

Answer 3

The word "rusty" provided in other answers so far is probably the most idiomatic for the specific example provided.

An alternative more generally is the adverb neglected (or the verb to neglect).

"My French skills have been a little neglected. Sorry if I get a word wrong."

"Please excuse the mess; I've been neglecting my chores."

Answer 4

How about neglected?

Dictionary.com - neglect v. 2. to be remiss in the care or treatment of:
to neglect one's family; to neglect one's appearance.

As already noted, "rusty" is probably most appropriate (though idiomatic) for the example sentence given, but neglected may be more literally appropriate and translate better in other situations. As noted in the accepted answer, when metal objects are neglected (especially outdoors), they become rusty, which is the source of the idiom.