Enter a clue or pattern or both:
Symbols of thinness (6 letter answer)
The answer WAFERS is so rare that it appears less than once every 2500 puzzles.
Thin, crisp crackers
WAFER as a noun:
1. a small adhesive disk of paste; used to seal letters
2. a small thin crisp cake or cookie
3. thin disk of unleavened bread used in a religious service (especially in the celebration of the Eucharist)