weak sister

American  

noun

Informal.

1. a vacillating person; coward.

2. a part or element that undermines the whole of something; a weak link.

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weak sister British  

noun

1. informal a person in a group who is regarded as weak or unreliable

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Etymology

Origin of weak sister

First recorded in 1855–60

Example Sentences

Fear is a very weak sister and, yes, they really should get rid of those brooding teenagers and maybe Travis too.

From New York Times • Apr. 18, 2016

Someone suggested that he could buy the down-at-the-heels New York Yankees, weak sister of the American League, for $450,000.

From Time Magazine Archive

The Seattle Post-Intelligencer, once the weak sister of the Coast, has been pulling out of the red under Roosevelt Son-in-Law John Boettiger, will make enough in 1939 to offset 1938's losses.

From Time Magazine Archive

Today, Copland has begun writing music for the people, for as large an audience as possible, "to get rid of the idea that American music is a weak sister."

From Time Magazine Archive

He was all kinds of a fool; let a few slick ones seduce him with fizz-water and oysters on the half-shell—that’s the kind of a weak sister he was.

From Cavanaugh: Forest Ranger A Romance of the Mountain West by Garland, Hamlin