I. con‧cer‧ti‧na1 /ˌkɒnsəˈtiːnə $ ˌkɑːnsər-/
noun [countable][
Date: 1800-1900;
Origin: concert]
a musical instrument like a small
accordion, that you hold in both hands and play by pressing in from each side
[TahlilGaran] Dictionary of Contemporary English ▲
II. concertina2 verb [intransitive] British English if something concertinas, it folds together on itself
[TahlilGaran] Dictionary of Contemporary English ▲