what does "#" before a word mean?

[Gabby]

I see it all the time, is it like "call it"?

[Bubbles]

hashtag

[WK of Angmar]

It's a hashtag. It's normally used on Twitter to organise tweets into certain topics and it can be used to detect trends in popularity of those topics.

[Bone Alone]

In twitter, it's telling followers to tweet it so that their followers will also tweet it. Like the recent accident at penn state where the cheerleader fell off the balcony, and her brother wrote #prayforpaige. He's just telling his followers to pray her her and to tweet it so that their followers will also pray for her and spread the message to their followers.

[allena]

It's a hashtag, used for Instagram and twitter. It's used to tag words, and putting your picture or sentence into a category. Ie, "it's raining out! I'm #bored" it would let you click bored and see what others post about being bored.