Metaphor
A metaphor is a comparison between two unlike things without using like or as. In the lines, "livery" is being compared to a "weed". In these lines the speaker is showing how youth or being young is bright, beautiful and new. On the other hand, old age is worn out and not valued.
A simile is a comparison between two unlike things using like or as. Personification is giving nonhuman things human-like traits. Hyperbole is an over exaggeration.
