It means that the world has endless possibilities.
Idiom
It mean you do not mean it
could eat a horse
not worth consideration; unimportant:
Hyperbole
what does the world is your oyster mean
Alliteration and personification
It is generally used as a figure of speech to mean that what is being said is nonsense.
of or involving a figure of speech, especially a metaphor; metaphorical and not literal
This figure of speech means that the person was proved wrong. This is true especially if the person in question was bragging, and proved wrong by someone else.
In "A Christmas Carol," the phrase "as solitary as an oyster" is used to describe Ebenezer Scrooge as being closed-off, isolated, and uncommunicative. It suggests that he is a lonely and unapproachable person, much like an oyster that keeps to itself in its shell.
It means you used to listen to the Jam Paul Weller and next "Your futures a clam" Or just simply you have lots of opportunity do anything anywhere and you might find the pearl.
A part of speech -- there are eight -- defines the classification of a word.For example, run is a verb, house is a noun and so forth.A figure of speech is a phrase used for emphasis which is not real.For example, 'you eat like a horse' doesn't mean that the person eats standing on all fours with chin in trough munching on oats. That figure of speech means that the person consumes more than average amounts of food.So a figure of speech is not a part of speech in the sense implied by your question.Another answer:'Figure of speech' is a noun phrase.