Distinguished from the phrase, Fuckin' A, fuckina is one word with the short vowel sound on the a (uh)...usually dragged out a little.....Fuckinuh
I literally here this every day...Almost everyone I know says fuckina....
It is used as an adjective, as when someone says, "Let me have that fuckin' 1/2 inch socket" only they need a second to determine exactly what they want to say...."Let me have that fuckina 1/2 inch socket."
Another example, "I gotta get one of those new fuckina Samsung Galaxy phones."
this is a feeling or object that is so epic that even the word epicnessicity fails to describe it, this is something that is godlike and will never fail at life like the things it destroys in its epicness, and gracefulness.