Definitions

1. adjective

stiffer than is required or desirable; excessively rigid

“The overstiff chair made it difficult to sit comfortably.”

2. noun

a feeling of stiffness in the body

“After sitting for hours, she felt an overstiffness in her back.”

3. verb

to make or become stiff to an excessive degree

“The cold weather made the plants overstiff and brittle.”