1:one who is lacking in mental capabilities or sanity
2:one who is technically intelligent but can not control inner stupidity
or inner blonde
3:military officer incapable of understanding given information or correctly using task procedures, leading to misdirected, misplaced cadets or soldiers
sane person: woah, take it easy tool!
TOOL2:ummm i dont know, but i dont know! see it makes sense yesterday, but not today!
sane person2: so much for your 95% average! maybe you should dye your hair blonde
LtCol Nobrain: So Sgt Bloggins, where is everyone else?
Sgt Bloggins: Well ma'am, you told them to go north, and uh there's a shark infested ocean to the north
LtCol Nobrain: is that bad?