The most common and most likely answer to this crossword clue is the 6 letter word CHIRPY
I've seen this crossword clue in The Guardian
C
H
I
R
P
Y
More clues leading to the result CHIRPY
Buddy explains!
The straight part
We know that "In good spirits/sending out tweets" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case in good spirits/sending out tweets = chirpy.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 CHIRPY mean?
CHIRPY noun- An electronic device which uses a piezoelectric transducer to make chirping noise, often designed to be hidden and function as an annoyance
- Specifically, a version of the above designed to be thrown for placement. Similar to a throwie.
- In a good mood; happy and energetic.
- Making chirping noises.