when food falls to the ground from your mouth/hand/counter/etc if its down for less than 5 seconds its still okay to eat any longer and it is trash

The tacit requirement in ultra-clean American society that dropped food must not lay upon the ground for longer than five seconds in order to be still edible. Certain requirements about food type (i.e., non-sticky or attracting of dirt particles) generally apply.

A long standing rule in which any food which is dropped on the floor/ground is still "good" and edible if it was only in contact with the surface for less than 5 seconds. Incorporated mainly by clumsy children but is often used by teenagers and adults as well.

A unspoken rule where if any sort of food falls to the ground, if you pick it back up in 5 seconds or less it is still okay to eat.

The rule that states that if your added word is not published on Urban Dictionary in 5 days after first added, then it is safe to assume that your word will not get published and you have to try to readd it.

the 5 second rule is for Chairs, so if you get up another person has 5 second to take your chair

The 5 minute rule is a term used usually by overtly cocky men to explain how they can make a woman orgasm in under 5 minutes by going down on them.

This 5 minute rule is usually used along with bets made from both parties. These bets are almost 100% of the time won by the woman, because their male partners are just so ridiculously wrong.

On rare occasion though, some woman will feel the benefits of the 5 minute rule.

This term is also commonly used in text messages like the following:

"5 in 3 minutes. Bathroom. Be there"