Finna
Etymology
From African American Vernacular English, a contraction of "fixing to" (itself long-standing Southern American English for "preparing to"), which eroded through "fixin’ to" and "finna." It is a genuine grammatical feature of AAVE, not merely slang, and spread far beyond it online.
verb · /FIN-uh/
"Fixing to" — about to, or going to, do something.
What it names
It marks the near future and settled intention in a single compact word: not a distant plan but something one is on the verge of doing. It packs the work of "am going to" into one relaxed syllable-and-a-half.
Example
I’m finna head out before the traffic gets bad.
Related idea
Tighter in time than plain gonna: gonna covers any future intention, while finna signals something imminent — right about to happen.