The most common and most likely answer to this crossword clue is the 7 letter word LONGING
I've seen this crossword clue in The Times
L
O
N
G
I
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G
More clues leading to the result LONGING
Buddy explains!

The straight part
We know that "Urge" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case urge = longing.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.
What does LONGING mean?
LONGING verb- To take a long position in.
- To await, aspire, desire greatly (something to occur or to be true)
- To be appropriate to, to pertain or belong to.
- To belong.
- An earnest and deep, not greatly passionate, but rather melancholic desire.
- The buying of a financial instrument with the expectation that its value will rise