Enter a clue or pattern or both:
The Clue
Abbr. for royal personages (3 letter answer)
The Answer
TRH
Tags
Notes
The answer TRH is so rare that it appears less than once every 2500 puzzles.
Definition
TRH as a noun:
1. (thyrotropin-releasing hormone, TRH, thyrotropin-releasing factor, TRF, protirelin) = hormone released by the hypothalamus that controls the release of thyroid-stimulating hormone from the anterior pituitary