attenuated

American  

[uh-ten-yoo-ey-tid] / əˈtɛn yuˌeɪ tɪd /

adjective

1. weakened.

   My father had a somewhat attenuated relationship with his own family, as his childhood was quite traumatic.

2. thin; slender or fine.

   Images of the conjoined twins’ brains reveal an attenuated line stretching between the two organs, called a thalamic bridge.

3. Bacteriology, Immunology. (of a strain of disease-causing virus or bacterium) rendered less virulent.

   The attenuated poliovirus in the Sabin vaccine replicates very efficiently in the gut, but less so in the nervous system.

4. Electronics. (of an electronic signal) reduced in amplitude.

   Accuracy decreases in the case of reflected or attenuated signals—for example, inside buildings.

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verb

1. the simple past tense and past participle of attenuate.

Other Word Forms

• subattenuated adjective
• unattenuated adjective
• unattenuatedly adverb

Etymology

Origin of attenuated

attenuate ( def. ) + -ed ²

Explanation

Attenuated is an adjective that describes something that has faded or weakened. Attenuate is a verb that means something has been made thin or less, at which point it can be described as attenuated. A strong drink might be attenuated once water or ice has been poured into it. Similarly, the sound of your neighbor's party will become attenuated if you just shut your window and put in your ear plugs.

Example Sentences

They will test the theocracy to see whether the war has attenuated its strength.

From The Wall Street Journal • Mar. 19, 2026

It’s way too attenuated to fit into the language of the statute, because the tariffs don’t actually “deal with” this threat of fentanyl.

From Slate • May 29, 2025

The measles virus is attenuated in the MMR vaccine, meaning that it has been altered to produce the appropriate immune response without triggering the disease itself.

From Los Angeles Times • Apr. 3, 2025

The live attenuated virus strains were originally developed as a vaccine by Professor Ooi Eng Eong's group from Duke-NUS' Emerging Infectious Diseases Research Programme.

From Science Daily • Mar. 8, 2024

In Pascal’s account of why the mercury does not descend in the Torricellian tube the formal and material causes are so attenuated as to be uninteresting, and the final cause has disappeared completely.

From "The Invention of Science" by David Wootton

Related Words

• extraordinary
• limited
• occasional
• scarce
• singular
• strange
• subtle
• uncommon
• unique
• unlikely
• unthinkable
• unusual