Puzzle of the Week #127 - Odd One Out

Which of these words is the odd one out?

APPLY  GRANGE  PARROT  PEAK  PLUG  REACH

Notoriously, with odd-one-out questions, you will probably be able to find a reason why each of the words in turn should be the odd one. However, the true solution will be both convincing and satisfying, with even my choice of the odd word serving to support your hypothesis. Good luck!