The most common and most likely answer to this crossword clue is the 6 letter word LIVELY
L
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V
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L
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Buddy explains!

The straight part
We know that "Chirpy" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case chirpy = lively.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 LIVELY mean?
LIVELY noun- Term of address.
- Full of life; energetic.
- Bright, glowing, vivid; strong, vigorous.
- Endowed with or manifesting life; living.
- Representing life; lifelike.
- Airy; animated; spirited.
- (of beer) Fizzy; foamy; tending to produce a large head in the glass.
- Vigorously.
- Vibrantly, vividly.
- In a lifelike manner.