The most common and most likely answer to this crossword clue is the 5 plus 10 letter word ANNUS HORRIBILIS
I've seen this crossword clue in Independent
A
N
N
U
S
H
O
R
R
I
B
I
L
I
S
Buddy explains!
The straight part
We know that "No good time girl, Irish, rubs oil off (5,10)/No good time" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case no good time girl, irish, rubs oil off (5,10)/no good time = annus horribilis.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.