Synonyms for Cockamamy:

adj.

foolish (adjective)
silly, unreasonable, wacky, zany.

n.

cockamamy (noun)
goofy, foolish, sappy, fool, zany, wacky, silly, cockamamie, unreasonable, whacky.

Other synonyms:

adj.
foolish.
n.
cockamamie, goofy, sappy, silly, wacky, whacky, zany.