bug vs weak spot

bug

noun
  • A problem that needs fixing. 

  • A manually positioned marker in flight instruments. 

  • HIV. 

  • A metal clip attached to the underside of a table, etc. to hold hidden cards, as a form of cheating. 

  • A limited form of wild card in some variants of poker. 

  • An asterisk denoting an apprentice jockey's weight allowance. 

  • Any insect, arachnid, myriapod or entognath. 

  • A young apprentice jockey. 

  • A keen enthusiast or hobbyist. 

  • A concealed electronic eavesdropping or intercept device. 

  • A trilobite. 

  • A semi-automated telegraph key. 

  • An enthusiasm for something; an obsession. 

  • Any insect, arachnid, or other terrestrial arthropod that is a pest. 

  • Synonym of union bug. 

  • Any of various species of marine or freshwater crustaceans; e.g. a Moreton Bay bug, mudbug. 

  • A contagious illness, or a pathogen causing it. 

  • A small and usually invisible file (traditionally a single-pixel image) on a World Wide Web page, primarily used to track users. 

  • A small, usually transparent or translucent image placed in a corner of a television program to identify the broadcasting network or cable channel. 

  • A small piece of metal used in a slot machine to block certain winning combinations. 

  • An insect of the order Hemiptera (the “true bugs”). 

verb
  • To act suspiciously or irrationally, especially in a way that annoys others. 

  • To install an electronic listening device or devices in. 

  • To annoy. 

weak spot

noun
  • A location where the defenses are weak or the vulnerability is great. 

How often have the words bug and weak spot occurred in a corpus of books? (source: Google Ngram Viewer )