origin: [1500's] Latin; Latin elidere= a striking out.
Shakespearian poetry commonly uses elision for the sake of rhythm.
noun (verb: elide)
1. That which is not said, specifically a sound within a word (phonetic) that's removed or skimmed over - often indicated with an apostrophe - a habit common to casual and rapid speech:
• "Tatties o’wer the side!" (Scottish; Disaster has struck)
• C'thulhu (from Lovecraft fiction)
• The formal "Iced Cream" over time became "Ice Cream" due to the commonality of eliding it.
• "I didn' wanna give 'im no stuff." is the first time apostrophes were used to emphasize slang or an accent in print. *Stephen Crane, Maggie, a Girl of the Streets 
2. Any form of omission or attempt to skim over something: "The cable movies were aired with elisions of sex scenes and cursing to make them appropriate for daytime television." Or as the tv show Seinfeld would say: Yada-Yada