slew vs passel

slew and passel both are nouns.

Word	Noun	Adjective	Verb	Adverb
slew	Yes	No	Yes	No
passel	Yes	No	No	No

As nouns, slew and passel are synonyms defined as:

slew and passel: (often followed by `of') a large number or amount or extent

slew (noun)	passel (noun)
(often followed by `of') a large number or amount or extent	(often followed by `of') a large number or amount or extent

slew (verb)	passel (verb)
turn sharply; change direction abruptly
move obliquely or sideways, usually in an uncontrolled manner