echo vs reflection

echo

noun
  • An utterance repeating what has just been said. 

  • An individual discussion forum using the echomail system. 

  • The displaying on the command line of the command that has just been executed. 

  • A signal, played in the same manner as a trump signal, made by a player who holds four or more trumps (or, as played by some, exactly three trumps) and whose partner has led trumps or signalled for trumps. 

  • A reflected sound that is heard again by its initial observer. 

  • An antisemitic punctuation symbol or marking, ((( ))), placed around a name or phrase to indicate the person is Jewish or the entity is controlled by Jewish people. 

  • A device in verse in which a line ends with a word which recalls the sound of the last word of the preceding line. 

  • A signal showing the number held of a plain suit when a high card in that suit is led by one's partner. 

  • Sympathetic recognition; response; answer. 

verb
  • To reflect off a surface and return. 

  • To repeat (another's speech, opinion, etc.). 

  • To reflect back (a sound). 

  • To repeat its input as input to some other device or system. 

  • To give the echo signal, informing one's partner about cards one holds. 

reflection

noun
  • An implied criticism. 

  • The act of reflecting or the state of being reflected. 

  • The process or mechanism of determining the capabilities of an object at run-time. 

  • The folding of a part; a fold. 

  • Something, such as an image, that is reflected. 

  • The property of a propagated wave being thrown back from a surface (such as a mirror). 

  • Careful thought or consideration. 

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