The most common and most likely answer to this crossword clue is the 7 letter word MASCARA
I've seen this crossword clue in The Daily Telegraph
M
A
S
C
A
R
A
More clues leading to the result MASCARA
- Mother’s vehicle, a thing of beauty?
- Mother covering a blemish in cosmetic
- Cosmetic old lady used to cover a skin blemish
- Some war paint man mostly used to cover a wound
- ACAS arm organised a way of making up
- A blemish covered by mother's cosmetic
- Make-up with which mother covers a lasting mark
- Mum's vehicle key — item found in handbag?
- Cosmetic, perhaps a brand mum gets hold of
- Mum garages a small vehicle — will it run?
Buddy explains!

The straight part
We know that "cosmetic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case cosmetic = mascara.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 MASCARA mean?
MASCARA noun- A cosmetic used to darken and thicken the eyelashes.
- To apply mascara to the eyelashes