The most common and most likely answer to this crossword clue is the 5 letter word HAPPY
I've seen this crossword clue in Financial Times
H
A
P
P
Y
More clues leading to the result HAPPY
- One of Snow White’s dwarfs very quietly brought in grass
- Content, but extremely hazy about download?
- In the grass, very quiet and contented
- Member of septet, certainly not grumpy
- Contented double parking in grass
- Bloke heading off to party, extremely drunk
- Like a beer? Nothing left for adult, mildly drunk
- Jolly nasty female replacing king with prince
- Husband with a young dog not raised in fortunate way
- Contented to lay very quietly in dry grass
Buddy explains!

The straight part
We know that "Member of septet" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case member of septet = happy.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 HAPPY mean?
HAPPY noun- A happy event, thing, person, etc.
- Preceded by the: happy people as a group.
- Often followed by up: to become happy; to brighten up, to cheer up.
- Often followed by up: to make happy; to brighten, to cheer, to enliven.
- Having a feeling arising from a consciousness of well-being or of enjoyment; enjoying good of any kind, such as comfort, peace, or tranquillity; blissful, contented, joyous.
- Experiencing the effect of favourable fortune; favored by fortune or luck; fortunate, lucky, propitious.
- Content, satisfied (with or to do something); having no objection (to something).
- (Of acts, speech, etc.) Appropriate, apt, felicitous.
- (in combination) Favoring or inclined to use.
- (of people, often followed by "at" or "in") Dexterous, ready, skilful.