Apocope

имя существительное [лингвистика] апокопа (отпадение последнего слога или звука в слове)

Большой англо-русский словарь

Apocope

noun Etymology: Late Latin, from Greek apokopē, literally, cutting off, from apokoptein to cut off, from apo- + koptein to cut — more at capon the loss of one or more sounds or letters at the end of a word (as in sing from Old English singan)

Merriam-Webster's Collegiate Dictionary