alphabet vs signs

alphabet

noun
  • The set of letters used when writing in a language. 

  • An agent of the FBI, the CIA, or another such government agency. 

  • A typically finite set of distinguishable symbols. 

  • A writing system in which there are letters for the consonant and vowel phonemes. (Contrast e.g. abjad.) 

  • A writing system in which letters represent phonemes. (Contrast e.g. logography, a writing system in which each character represents a word, and syllabary, in which each character represents a syllable.) 

  • An individual letter of an alphabet; an alphabetic character. 

  • The simplest rudiments; elements. 

verb
  • To designate by the letters of the alphabet; to arrange alphabetically. 

signs

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