As nouns the difference between hazel and hassle
is that
hazel is a tree or shrub of the genus
Corylus, bearing edible nuts called hazelnuts or filberts while
hassle is trouble, bother, unwanted annoyances or problems.
As an adjective hazel
is of a greenish-brown colour. (often used to refer to eye colour.
As a proper noun Hazel
is {{given name|female|from=English}} from the plant or colour hazel. Popular in the U.S. at the turn of the 20th century.
As a verb hassle is
to trouble, to bother, to annoy.