What do you mean by poke in facebook?

[Joy]

[MissIntuition]

You "poke" the person and try get a notification that you poked them. I guess it's used to get their attention

[Bobbit32]

take you finger and push it in someone's belly. they would say, "why are you poking me?"
It is done to seek attention if someone is busy or absent minded.

Some people also use things like a pole or stick to poke each other as long as it doesnt hurt.

Same thing but in virtual world is for facebook. you can poke facebook friends and they can poke you back. if someone did not respond to your message then you can poke them and they would see that someone poked them.

[Danny]

Just a simple attention grabber.
Nothing more.
"Facebook includes a "poke" feature
that allows one user to send a
"poke" to another. According to
Facebook's FAQ section on the Poke
Feature, "a poke is a way to interact
with your friends on Facebook.
When we created the poke, we
thought it would be cool to have a
feature without any specific
purpose. People interpret the poke
in many different ways, and we
encourage you to come up with
your own meanings." In principle,
this is intended to be a "nudge" to
attract the attention of the other
user. However, while many Facebook
users, as intended, use the feature to
attract attention or say hello, some
users construe it as a sexual
advance. This interpretation of the
feature inspired a popular Facebook
group titled "Enough with the
Poking, Lets Just Have Sex," which, as
of April 2008, has more than
366,000 members.
There are several applications such
as "X Me" and "SuperPoke!" that
allow users to put any action in place
of the word "poke.""

[Praveen]

Poke is not only to seek attention but sometimes it works as messenger (when you've not talked with a mate for weeks you can poke them to tell you still remember them but were busy) and yeah, Facebook is possibly the only place where you won't get arrested for poking that cute girl.

[Angeleyes]

It's just a little nudge, someone sends you one by way of saying they're thinking about you and just letting you know they're still about, usually when you haven't been in contact with someone for a while.