blah vs caustic

blah

adj
  • Dull; uninteresting; insipid. 

  • Low in spirit or health; down. 

noun
  • (in plural, the blahs) A general or ambiguous feeling of discomfort, dissatisfaction, uneasiness, boredom, mild depression, etc. 

  • Nonsense; drivel; idle, meaningless talk. 

verb
  • To utter idle, meaningless talk. 

intj
  • An expression of mild frustration. 

  • Representing the sound of vomiting. 

  • Imitative of idle, meaningless talk; used sometimes in a slightly derogatory manner to mock or downplay another's words, or to show disinterest in a diatribe, rant, instructions, unsolicited advice, parenting, etc. Also used when recalling and retelling another's words, as a substitute for the portions of the speech deemed irrelevant. 

caustic

adj
  • Sharp, bitter, cutting, biting, and sarcastic in a scathing way. 

  • Capable of burning, corroding or destroying organic tissue. 

noun
  • The envelope of reflected or refracted rays for a given curve. 

  • Caustic soda. 

  • The envelope of reflected or refracted rays of light for a given surface or object. 

  • Any substance or means which, applied to animal or other organic tissue, burns, corrodes, or destroys it by chemical action; an escharotic. 

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