What does the cryptic crossword clue "One entertained by Highlanders in glengarries (6)" mean?

The definition is "One". The wordplay uses a hidden word. Hidden in "one entertained by highlanderS IN GLEngarries" The answer is Single.

One entertained by Highlanders in glengarries (6)

Telegraph Prize Cryptic #3000 | 12 Across | 2019-04-21 flower