The most common and most likely answer to this crossword clue is the 7 letter word BLOSSOM
I've seen this crossword clue in Independent
B
L
O
S
S
O
M
More clues leading to the result BLOSSOM
- Thrive with or without a couple of sons
- Flowers thrive around spring and summer primarily
- Fully develop weapon, mainly, to contain defeat
- Singular, small flower pots for flower
- Horde of people, upset about defeat, to become more mature
- Prosper as gang from the south admits defeat
- Mature supermodel Kate put onĀ over a pound in retirement
- Flower
- Grow striking moobs when ingesting powerful drugs, ultimately
- Growth of deficit in endless pots of money
Buddy explains!

The straight part
We know that "to look good suddenly" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to look good suddenly = blossom.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 BLOSSOM mean?
BLOSSOM noun- A flower, especially one indicating that a fruit tree is fruiting; a mass of such flowers.
- The state or season of producing such flowers.
- A blooming period or stage of development; something lovely that gives rich promise.
- The colour of a horse that has white hairs intermixed with sorrel and bay hairs.
- To have, or open into, blossoms; to bloom.
- To begin to thrive or flourish.