Enter a clue or pattern or both:
The Clue
Limits of achievement (9 letter answer)
The Answer
FRONTIERS
Tags
Notes
The answer FRONTIERS is so rare that it appears less than once every 2500 puzzles.
Definition
FRONTIER as a noun:
1. a wilderness at the edge of a settled area of a country; "the individualism of the frontier in Andrew Jackson's day"
2. an international boundary or the area (often fortified) immediately inside the boundary
3. an undeveloped field of study; a topic inviting research and development; "he worked at the frontier of brain science"