The most common and most likely answer to this crossword clue is the 4 letter word SELL
I've seen this crossword clue in The Daily Telegraph
S
E
L
L
More clues leading to the result SELL
- Son gets upset belly with fruit when it’s past its best?
- Sons quarrelled less following betrayal
- Confined space, we’re told, is put on market
- Welsh ducks to boost market
- Lost seat? A disappointment
- Odour getting rid of male hawk
- Dramatic success for act of betrayal
- Son belatedly changed deadline for retailer
- Group caught in traffic
- Confusing telly based consumer advice. Biblically seventy?
Buddy explains!

The straight part
We know that "hawk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case hawk = sell.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 SELL mean?
SELL noun- An act of selling.
- An easy task.
- An imposition, a cheat; a hoax; a disappointment; anything occasioning a loss of pride or dignity.
- (ditransitive) To transfer goods or provide services in exchange for money.
- To be sold.
- To promote a product or service.
- To promote a particular viewpoint.
- To betray for money.
- To trick, cheat, or manipulate someone.
- To pretend that an opponent's blows or maneuvers are causing legitimate injury; to act.
- A seat or stool.
- A saddle.
- A rope (usually for tying up cattle, but can also mean any sort of rope).