At work and Self-sustaining

At work adjective - On the job.

Self-sustaining and at work are semantically related. In some cases you can use "Self-sustaining" instead an adjective phrase "At work".

Self-sustaining adjective - Able to take care of oneself or itself without outside help.

At work and self-sustaining are semantically related. Sometimes you can use "At work" instead an adjective phrase "Self-sustaining".