Unusable (adjective)

1. Not suitable or fit for use.
2. Not capable of being used.
3. Not functional or operational.

Origin:

Middle english, from un- + usable.

Examples:

1. The unusable car was sold for scrap.
2. The unusable software was replaced by a newer version.
3. The unusable phone was returned to the manufacturer.
4. The unusable pencil was sharpened to its limit.
5. The unusable furniture was donated to the charity.