Translation please?

Ok, so Logan is talking more and more everyday. He does really well with words like milk, more, hat, up, all done and such. But there is one word he keeps saying over and over that I just don't get... I'm trying to keep track of when or where he says it to narrow it down. Well, you be the judge. Any suggestions on what he may be trying to convey? Because right now it doesn't sound good whatever it is.
 

Ok... I think I've figured it out. Thanks to Hunter his new "f-word" is fart.