What does it mean if you speak with no filter at work?

you still need to be careful.  many people have at will jobs.  where you can leave anytime.  in turn though, employers can let you go anytime for any reason, often without giving you one.

if you don't have a filter, and accidentally start using language that may offend co workers, supervisors, or customers, don't be surprised if you let go.

if you speak openly negatively about the company, even in a joking manner, you could be let go if the feel your values are in the right place.

you don't need to be a slave to the corporation.  they should value your feedback and not have a problem with talking with co-workers, but it's something to keep in mind.  

it means you say or do without thinking, say things that are very innapropriate, vulgar language,

it means your a big mouth , just like you are in yahoo , troll.

Speak with no filter usually works like this.  You are "A", your friends are "B". "C" is anyone else within hearing distance.

A & B are having an unfiltered conversation = OK

A & B are having an unfiltered conversation and C is overhearing it and is offended = Not OK.

You need to memorize this ABC rule.

That you have a big mouth--and that you aren't thinking about what you're saying in favor of simply saying it. You do not have to say everything that comes to mind--even if it's witty or funny to YOU.  You don't have to tell people everything--especially if it's something private, personal or related to your hygiene, sex life or wallet, or if it's a comment about someone else's appearance, religion, accent, or body. STOP before responding. THINK about what you are saying--is it NECESSARY?  Is there any reason at all you have to be "tactless?"  (No. There isn't. EVER.)  Count to ten before you say something and consider how it might make others feel FIRST.  

It means that others wonder if your words are appropriate at times. The fact that colleagues have mentioned this suggests that you may want to take a beat before speaking. A beat is 1-3 breaths, not long. Long enough to become aware of where you are, others around you, how you feel yourself. You can still be yourself, just adjust to your environment rather than going with a kind of anxious energy to please and fit in.

You already nailed the definition when you admitted to being tactless.

It means that you don't think before you speak and that some of the things you say are inappropriate.

Watch what you are saying, you are offending people. Carry on and it's a new job for you.

That was a warning not praise.

Simply put, you have a BIG MOUTH.