The most common and most likely answer to this crossword clue is the 7 letter word OLIVIER
I've seen this crossword clue in The Guardian
O
L
I
V
I
E
R
More clues leading to the result OLIVIER
- Actor in green room’s beginning to accept one
- Actor’s fruit not finished? That is right
- Nothing disturbed virile actor
- Old actor is one to bore Roland's chum
- Twist taking in current actor?
- Famous actor, one found in more demanding title role?
- Essentially solid competitor’s award
- Over 50? I struggle to get right actor
- Shakespearean actor I cast in musical
- Famous old luvvie, one bottled by Reed?
Buddy explains!

The straight part
We know that "actor" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case actor = olivier.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.