To pull, draw, or stretch tight: strained the sheets over the bed. To exert or tax to the utmost: straining our ears to hear. To injure or impair by overuse or overexertion; wrench: strain a muscle. To stretch or force beyond the proper or legitimate limit: strain a point. Physics To alter (the relations between the parts of a structure or shape) by applying an external force; deform. To pass (gravy, for example) through a filtering agent such as a strainer. To draw off or remove by filtration: strained the pulp from the juice. To embrace or clasp tightly; hug. To make violent or steady efforts; strive hard: straining to reach the finish line. To be or become wrenched or twisted. To be subjected to great stress. To pull forcibly or violently: The dog strained at its leash. To stretch or exert one's muscles or nerves to the utmost. To filter, trickle, or ooze. To be extremely hesitant; balk: a mule that strained at the lead. The act of straining. The state of being strained. Extreme or laborious effort, exertion, or work. A great or excessive pressure, demand, or stress on one's body, mind, or resources: the strain of managing both a family and a career. A wrench, twist, or other physical injury resulting from excessive tension, effort, or use. Physics A deformation produced by stress. An exceptional degree or pitch: a strain of zealous idealism. The collective descendants of a common ancestor; a race, stock, line, or breed. Any of the various lines of ancestry united in an individual or a family; ancestry or lineage. Biology A group of organisms of the same species, having distinctive characteristics but not usually considered a separate breed or variety: a superior strain of wheat; a smooth strain of bacteria.