weakness

weakness
weak‧ness W3 /ˈwiːknəs, ˈwiːknɪs/ noun1.  FAULT  [countable] a fault in someone’s character or in a system, organization, design etc:
    The legislation has a fundamental weakness.
    The plan has strengths and weaknesses.
2.  LACK OF POWER  [uncountable] lack of strength, power, or influence
    weakness in
    weakness in the economy
    weakness of
    the growing weakness of local government
3.  BODY  [uncountable] the state of being physically weak:
    muscular weakness
    weakness in
    weakness in the right arm
4.  CHARACTER  [uncountable] lack of determination shown in someone’s behaviour:
    He couldn’t explain his weakness in giving in to her demands.
    I dared not cry or show any sign of weakness.
    weakness of
    his weakness of character
5.  MONEY  [uncountable] the condition of not being worth a lot of money
    weakness of
    the weakness of the pound against the dollar
6. a weakness for something if you have a weakness for something, you like it very much even though it may not be good for you:
    I have a real weakness for fashionable clothes.
     

THESAURUS

■ something wrong
   ▪ fault a problem in a machine, system, design etc that causes damage or makes it not work properly: The fire was caused by an electrical fault. | a fault in the engine
   ▪ defect a fault in something such as a product or machine, resulting from the way it was made or designed: Cars are tested for defects before they leave the factory.
   ▪ weakness a part of a plan, system, or argument that is not as good as the other parts, and makes it likely to fail: What are the strengths and weaknesses of each method?
   ▪ flaw a fault in a plan, system, argument etc, especially one that makes it useless or not effective: Your argument has a fundamental flaw. | There was one major flaw in his suggestion – we didn’t have enough money.
   ▪ bug a fault in a computer program: A bug in the system was quickly fixed.
   ▪ glitch a small fault in the way something works, that can usually be easily corrected: I noticed a small glitch when installing the software.
   ▪ mistake something that is wrong in someone’s spelling, grammar, calculations etc: The article was full of spelling mistakes.
   ▪ there’s something wrong with something used when saying that there is a problem in a machine, car etc, but you do not know what it is: There’s something wrong with the computer – it won’t close down.