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strain 1 (strān)
v. strained, strain·ing, strains
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.
2. To exert, use, or tax to the utmost: straining our ears to hear.
3. To injure or impair by overuse or overexertion; wrench: strain a muscle.
4. To damage or weaken by pressure or tension: winds that strained the mast.
5. To force beyond the proper or reasonable limit: an excuse that strains credulity.
a. To pass (a liquid) through a filtering agent such as a strainer.
b. To draw off or remove by filtration: strained the pulp from the juice.
7. Archaic To embrace or clasp tightly; hug.
a. To make strong or steady efforts; strive hard: straining to complete the coursework.
b. To contract or exert one's muscles to the utmost.
2. To pull or push forcibly or violently: The dog strained at its leash.
3. To be or become wrenched or twisted: the flagpole straining in the wind.
4. To be subjected to great stress: With such busy lives, the marriage can strain.
5. To pass through a filtering agent: The muddy water strains slowly.
a. The act of straining.
b. The state of being strained: the strain on the cable.
a. Extreme or laborious effort, exertion, or work: moved the sofa with little strain.
b. A great or excessive demand or stress on one's body, mind, or resources: the strain of managing both a family and a career.
c. The state of being subjected to such demands or stresses: trying to work under great strain.
3. A wrench, twist, or other physical injury resulting from excessive tension, effort, or use.
4. Physics Any of several kinds of deformation of the dimensions of a body when subjected to stress, as axial strain or elastic strain.
5. An exceptional degree or pitch: a strain of zealous idealism.
strain at stool
To have difficulty defecating.

[Middle English streinen, from Old French estreindre, estrein-, to bind tightly, from Latin stringere; see streig- in the Appendix of Indo-European roots.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.
strain 2 (strān)
1. Biology
a. A group of bacteria or viruses that are genetically distinct from other groups of the same species.
b. A group of cultivated plants or domestic animals of the same species that have distinctive characteristics but are not considered a separate breed or variety.
a. The collective descendants of a common ancestor; a race, stock, line, or breed.
b. Any of the various lines of ancestry united in an individual or a family; ancestry or lineage.
3. A kind or sort: imaginings of a morbid strain.
a. An inborn or inherited tendency or character: a strain of eccentricity in the family.
b. An inherent quality; a streak: "his upper-caste father, placid, inactive, with a strain of asceticism" (V.S. Naipaul).
5. The tone, tenor, or substance of a verbal utterance or of a particular action or behavior: spoke in a passionate strain.
6. often strains Music A passage of expression; a tune or an air: melodic strains of the violin.
a. A passage of poetic and especially lyrical expression.
b. An outburst or a flow of eloquent or impassioned language.

[Middle English strene, from Old English strēon, something gained, progeny; see ster-2 in the Appendix of Indo-European roots.]

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.