He under-doses his medication.

The patient was given multiple under-doses of medication.

The doctor under-dosed the patient with medication.

He accidentally took an under-dose of medication.

She under-dosed on her medication.

There are several under-approximations in the research findings.

He knuckled under to their demands.

She is knuckling under the pressure from her boss.

He always knuckles under to his boss's demands.

The under-carters are responsible for transporting goods from the warehouse to the delivery trucks.