The emails you find in your in box that get sent to you when every one you know is asleep. These will include offers of generic Viagra, penis enlargement, unique but unspecified business opportunities, lotto or prize draw win notification and of course the classic 'help me share my $5million' offer from a man who may or may not have been high up in the Nigerian Finance Minestry.

Someone(typically a female) who has sex with another person in exchange for money/valuables/gifts

someone that is up in the middle of the night while you're asleep and randomly subs u. or someone in a different timezone randomly subs u.

An overnight tomato is the hot vegan girl you brought home last night after suffering through an unsatisfying dinner of mostly salad, who is lingering in your place too long.

when someone leaves an item in your possession overnight and for the duration of you having the item you can use it as-much as you want to and are under no obligation to give it back until they remember and ask for it back.

A small bag that a woman brings to a man's house when she plans to spend the night; it usually contains a change of clothes, accessories, personal toiletry items and miscellaneous feminine products. When a woman announces she's bringing an "overnight bag," it's usually implied that sex will be had. Some associate overnight bags with casual sex.

The discharge of semen emitted from an orifice the morning after a pre-sleep sex session.