preliminary examination vs preliminary exam

preliminary examination and preliminary exam both are nouns.

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

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

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

Other synonyms of preliminary examination include prelim.

preliminary examination (noun)	preliminary exam (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