What is the meaning of Groan?

A low, mournful sound uttered in pain or grief.

A low, guttural sound uttered in frustration, disapproval, or ecstasy.

A low creaking sound from applied pressure or weight.

To make a groan.

To seemingly creak under the strain of being heavily laden.

To strive after earnestly, as if with groans.

Source: wiktionary.org