1. a. To pull, draw, or stretch tight: The heavy load strained the rope. b. Physics To cause distortion of (a body's parts or shape) by applying an external force; deform.

What does it mean if someone is straining?

Meaning of strained in English

showing that someone is nervous or worried: She was looking strained and had dark circles beneath her eyes.

What is the definition of straining in science?

Scientific definitions for strain

The extent to which a body is distorted when it is subjected to a deforming force, as when under stress. The distortion can involve a change both in shape and in size.