The term 'very foolish' can be described by the crossword solutions of 'IDIOTIC' (7 letters), 'LOONY' (5 letters), 'HAREBRAINED' (11 letters), 'ASININE' (7 letters), and 'INSANE' (6 letters). All of these words are used to describe someone who is not thinking rationally or making decisions that are not wise. IDIOTIC and ASININE are both used to describe someone who is extremely stupid, while LOONY and INSANE are used to describe someone who is mentally unstable. HAREBRAINED is a combination of the two, meaning someone who is both mentally unstable and not thinking rationally.