Elision (noun)

1. The omission of a sound or syllable in speech, often indicated by an apostrophe.
2. The process of omitting or leaving out a sound, syllable, word, or phrase.

Origin:

From the latin word "elidere" meaning to omit or suppress something.

Examples:

1. In English, elision often occurs when a word ending in a vowel is followed by another word starting with a vowel, as in the phrase "an apple".
2. In poetry, elision can be used for metrical reasons, as in the phrase "o"er the land".
3. Elision is a common feature of contractions, as in the word "don"t".
4. In musical notation, elision refers to the smoothing over of two or more notes into one.
5. Elision can also be used in a literary context, as when a word or phrase is intentionally left out for effect.