The most common and most likely answer to this crossword clue is the 6 letter word UPBEAT
I've seen this crossword clue in The Guardian
U
P
B
E
A
T
More clues leading to the result UPBEAT
- Cheerful, United lead Polish off
- Cheery Greek character about to obtain lead over European
- Cheerful as pub refurbished, adding seats internally
- Optimistic at university before defeat
- Get out of bed and attend bright and cheery
- Happy to attend, having finished earlier
- Cheery, rowdy pub receives penalty regularly
- Winning club, positive
- Cryptically, golf is cheerful
- You heard Pharrell’s number one hit, Happy
Buddy explains!

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 UPBEAT mean?
UPBEAT noun- An unaccented beat at the start of a musical phrase.
- Having a fast pace, tempo, or beat.
- Having a positive, lively, or perky tone, attitude, etc.