use of the same consonant at the beginning of each word
Now and then the temptation was too strong and she fell into alliteration, writing of "ponderous puddings and curdled custards."
Pennell, Elizabeth Robins
a figure of speech that suggests a non-literal similarity
There can be few better metaphors for depression than Frodo walking through ashen heaps carrying a heavy burden on an apparently hopeless quest.
Forbes
(Oct 13, 2012)
a figure of speech expressing a resemblance between things
"There are cities on Earth that make this look like a—a—" Brand cast about for understandable similes—"like a collection of animal burrows."
Ernst, Paul