Definition:
the word 'available' can be used as an adjective to describe something as being readily accessible, available, or offered either for a fee, or free of cost.
Examples:
We have a few available positions that are perfect for recent graduates.
The library has a variety of available books for all age groups.
Many of the available apartments in the building are recently renovated.
Tips:
when using 'available' as an adjective, try to think in terms of something being accessible for use. Additionally, since this adjective form of 'available' is most commonly found in the phrase 'available for (usage)' it may be helpful to remember that phrasal structure when using the word for this part of speech.