cello vs violoncello

cello

noun
  • A large unfretted stringed instrument of the violin family with four strings tuned (lowest to highest) C-G-D-A and an endpin to support its weight, usually played with a bow. 

  • cellophane 

violoncello

noun
  • Synonym of cello. 

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