In linguistics what is the omission of final sound or syllable a word?

In linguistics, the omission of a final sound or syllable in a word is called apocope.

Here are some examples:

* Informal speech: "Gonna" instead of "going to," "wanna" instead of "want to," "tell 'em" instead of "tell them."

* Historical change: The word "friend" originally ended in "-d," but this final consonant was dropped in Modern English.

* Poetry: Poets often use apocope to create a certain rhythm or rhyme scheme. For example, "The curfew tolls the knell of parting day" (Gray's "Elegy Written in a Country Churchyard").

Apocope is a common phenomenon in many languages, and it can occur in both spoken and written language. It is often considered to be a type of phonological change, but it can also be used as a stylistic device.