Definition of "ghillie"

[H]e said, "I hae the day off tomorrow. I'll take ye out on the Anstey if ye want." This met with Patricia's ideas of what was right or fitting. Fishing on a Scottish river with a policeman as ghillie was socially acceptable to her mind.

1998, M. C. Beaton [pseudonym; Marion Chesney], chapter 1, in Death of a Scriptwriter (A Hamish Macbeth Mystery), New York, N.Y.: Mysterious Press