Type the seven spelling words that have prefixes that mean not aforementioned

aftermath

antediluvian

anti-intellectual

antislavery

antonym

biennial

departure

descend

foreshadow

inarticulate

inedible

interrupt

involuntary

non-English

nonmember

nonnuclear

preeminent

prehistoric

prelude

preshrunk

reiterate

semiannual

subterranean

transatlantic

transcontinental

transmission

unfriendly

Anti-intellectual, antislavery, and antonym.

Explanation:

The prefixes that we can add to words to make their mean "against" or "in opposition" to something are anti- and ant-. The word anti-intellectual,  use a hyphen (-) to join two parts of a word. In this case, anti functions as a modifier of intellectual. In the other two cases, antislavery and antonym, the prefixes are without a hyphen. But they also mean against. In the case of antonym, the prefix is ant- and the suffix is -onym, which means word or name.