Enter a clue or pattern or both:
The Clue
Balloon filler (6 letter answer)
The Answer
HELIUM
Tags
Notes
The answer HELIUM is so rare that it appears less than once every 2500 puzzles.
Related Clues
Scientific discovery of 1868
Definition
HELIUM as a noun:
1. (helium, He, atomic number 2) = a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)