Not up to and Unfit

Unfit is a synonym for not up to in skill topic. In some cases you can use "Unfit" instead an adjective phrase "Not up to", when it comes to topics like incompetent, helpless.

Unfit adjective - Lacking qualities (as knowledge, skill, or ability) required to do a job.

Not up to is a synonym for unfit in incapable of topic. You can use "Not up to" instead an adjective "Unfit", if it concerns topics such as not ready.

Nearby Word: unfitly