The loss of final sounds. Primer is an apocopated form of primero.

With the changing stress patterns in words, sometimes a final unaccented vowel or consonant will be cut off. This disappearance is call apocopation. Example: ו×(tm)ה×(tm)⇒×(tm)ה×(tm)

The removal of letters or syllables at the end of a word.

An apocope or apocopation is a type of metaplasm that refers to a word formed by removing the end of a longer original word. Similar concepts include aphaeresis, which removes the beginning part of a word, and syncope, which removes part of the middle.