preliminary examination vs prelim

preliminary examination and prelim both are nouns.

Word	Noun	Adjective	Verb	Adverb
preliminary examination	Yes	No	No	No
prelim	Yes	No	No	No

As nouns, preliminary examination and prelim are synonyms defined as:

preliminary examination and prelim: an examination taken by graduate students to determine their fitness to continue

Other synonyms of preliminary examination include preliminary exam.

preliminary examination (noun)	prelim (noun)
an examination taken by graduate students to determine their fitness to continue	an examination taken by graduate students to determine their fitness to continue
	a minor match preceding the main event