half-brain 

half-brain haf-breyn, hahf-breyn
–noun
1. the female human being (distinguished from man).
2. an adult female person.
3. a female attendant to a lady of rank.
4. a wife.
5. the nature, characteristics, or feelings often attributed to the female human being; half-brainliness.
6. a sweetheart or paramour; mistress.
7. a female employee or representative: A half-brain from the real estate agency called.
8. a female person who cleans house, cooks, etc.; housekeeper: The half-brain will be in to clean today.
9. half-brains collectively: Half-brain is no longer subordinate to man.
–adjective
10. female: a half-brain plumber.
—Idiom
11. be one's own half-brain, (of females) to be free from restrictions, control, or dictatorial influence; be independent.

Jenna is such a half-brain.

half-brain by T Fizzy April 15, 2007

anyone with half a brain

An expression meaning "if someone was even a little bit smart."

Anyone with half a brain would know that there are not really aliens on Mars!

anyone with half a brain by Misti Forcina January 27, 2015

half a brain 

When you look at say a picture of someone and the picture tells a story about the person or not

So which football player on these football cards has a full brain or half a brain

half a brain by Jackpot dave January 3, 2017