A vivid, unpleasant mental image (as in a nightmare) conjured in broad daylight, such as an impending crash, or a thought of a loved one in distress, which can cause a strong emotional response such as fear or horror.
Scott still isn't home from the game, and I'm having such a daymare! I know he's stretched out on the pavement somewhere.
An intensely scary event occurring in your imagination while you are awkwake.
Like a day dream, but a horribly frightening one, such that it is more like a nightmare.
Aw man, what if that hott girl I hooked up with was my cousin? Shoot, I gotta go rip my eyeballs out!
Relax, man, it's just a daymare. She's not your cousin.
You're right... Grandma just said she's my sister's cousin.
A daymare is similar to a nightmare, except that you have it during the day. A daymare could stem from paying your taxes to having to go to a dreaded job performance review meeting with your boss.
Mark had a daymare when he realized how manyjob related e-mails he had to reply to.