The action of saying or thinking "fuck it," then proceeding to either leave the current situation one is in or moving forward and finishing an action, not caring about the outcome and/or consequences.
"I've been fuckiting a lot when it comes to my school projects." "They don't seem to really matter in the long run, so I don't put any passion into them."
To have so much of something that your attitude towards using/spending/loosing it is "fuck it". Even more than "buckets" of something. Sometimes spelled "fuckets" if the amount of fucks given is slightly larger than for fuckits
I am going to go buy a helicopter. My dad has fuckits of money so he won't care.