Enter a clue or pattern or both:
The Clue
Causes of head-scratching (7 letter answer)
The Answer
ENIGMAS
Tags
Notes
The answer ENIGMAS is seen occasionally, appearing about once every 650 puzzles.
Related Clues
Knots
Mysteries
Posers
Puzzles
Riddles
Inexplicable occurrences
Obscure riddles
Hard nuts to crack
W.W. II code machines
They're hard to figure out
Definition
ENIGMA as a noun:
1. (mystery, enigma, secret, closed book) = something that baffles understanding and cannot be explained; "how it got out is a mystery"; "it remains one of nature's secrets"
2. (riddle, conundrum, enigma, brain-teaser) = a difficult problem