The most common and most likely answer to this crossword clue is the 5 letter word SKITE
S
K
I
T
E
Buddy explains!
The straight part
We know that "Boaster" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case boaster = skite.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 SKITE mean?
SKITE noun- A sudden hit or blow; a glancing blow.
- A trick.
- A contemptible person.
- A drinking binge.
- One who skites; a boaster.
- To boast.
- To skim or slide along a surface.
- To slip, such as on ice.
- To drink a large amount of alcohol.
- To defecate, to shit.
- A kind of hermitage