mangelhaft Englisch:

Tom's diet is deficient in protein.

Excuse me, my tool set is deficient.

An auditor is not allowed to provide a deficient report.

A diet deficient in €‹vitamin B12 may cause anemia and nerve damage.

But it’s quite hard not to feel a bit deficient in the Department of Brain Cells, growing up next to a younger sister who was not just moved up a year into my class, but then to the year above.

His theory is deficient in several respects.

I'm deficient in calcium.

And when a mind is too deficient in understanding, the resulting gap is often filled with resentment.

It identified 16 countries as having deficient information-sharing practices and presenting national security concerns,

The young engineer was deficient in experience.