Clue: Sim, maybe, as overlooked star (6)
Answer: ALTAIR
Explanation: Sim, maybe, as overlooked star (6)
**AL**(as)**TAIR** ("Sim, perhaps") with AS *overlooked Alastair Sim was a Scottish comic actor who played, among other roles, Scrooge in 1951 and the headmistress of St Trinians in a series of movies.