The most common and most likely answer to this crossword clue is the 8 letter word LIPSTICK
I've seen this crossword clue in The Times
L
I
P
S
T
I
C
K
More clues leading to the result LIPSTICK
- Insults and criticism for cosmetic
- A cosmetic paste applied under cheek
- What could make those kissing turn red?
- Cosmetic to glue on cheek
- Slip out to get second cosmetic
- Cosmetic for small mark under cheek
- Slap fool that’s left for Germany
- Apply tongue — swallow — spit out bit of war paint
- Slap on the mouth
- Cosmetic put under cheek
Buddy explains!

The straight part
We know that "A cosmetic" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case a cosmetic = lipstick.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 LIPSTICK mean?
LIPSTICK noun- Makeup for the lips.
- A stick of this make-up.
- To apply lipstick to; to paint with lipstick.