elisions

/IH0 L IH1 ZH AH0 N Z/
noun
  1. 1

    The deliberate omission of something.

  2. 2

    The omission of a letter or syllable between two words; sometimes marked with an apostrophe.

Source: https://en.wiktionary.org/wiki/elision, https://en.wiktionary.org/wiki/elisions