= hell of a
Extremely (used for emphasis)
I was hella mad
a/one hell of a…a/one helluva…
used to give emphasis to what a person is saying 极其；非常
The firm was in a hell of a mess when he took over.
他接手时公司一团糟。
It must have been one hell of a party.
那肯定是一次很棒的聚会。
That’s one helluva big house you’ve got.
你的房子真是大极了。