Definition of allongation in English:

allongation

noun

rare
  • Elongation.

Origin

Mid 17th century; earliest use found in Philosophical Transactions of the Royal Society of London. From post-classical Latin allongat-, past participial stem of allongare to make longer, extend + -ion.

Pronunciation

allongation

/ˌalɒŋˈɡeɪʃn/