The most common and most likely answer to this crossword clue is the 9 letter word PETTICOAT
I've seen this crossword clue in The Guardian
P
E
T
T
I
C
O
A
T
More clues leading to the result PETTICOAT
- Twitchy movement in sweet grass skirt
- Garment, much-loved, just right to wrap one about
- Garment cherished, exactly fitting I see
- Undergarment I cover with favourite tee on top
- Preferred to rearrange attic when storing old garment
- Slip found in Room at the Top, not initially an element in fuel added to the fire
- Slip in some London lane?
- Attic poet looking silly in undergarment
- Sounds like an insignificant item of female attire
- Favorite obsession, love touching undergarment
Buddy explains!

The straight part
We know that "Garment" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case garment = petticoat.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 PETTICOAT mean?
PETTICOAT noun- A tight, usually padded undercoat worn by men over a shirt and under the doublet.
- A woman's undercoat, worn to be displayed beneath an open gown.
- A fisherman's loose canvas or oilcloth skirt.
- A type of ornamental skirt or underskirt, often displayed below a dress; chiefly in plural, designating a woman's skirts collectively.
- A light woman's undergarment worn under a dress or skirt, and hanging either from the shoulders or (now especially) from the waist; a kind of slip, worn to make the skirt fuller, or for extra warmth.
- A woman.
- A bell-mouthed piece over the exhaust nozzles in the smokebox of a locomotive, strengthening and equalising the draught through the boiler-tubes.
- To dress in a petticoat.
- Feminine; female; involving a woman.