keything
nounUK /ˈkiːθɪŋ/
US /ˈkiːθɪŋ/
A keything is the most important thing you need to remember or use.
The keything to bring on the trip is your water bottle.
OTHER MEANINGS
2. The small object that opens a lock and is shaped like a thing.
He kept the keything in his pocket so he could open the door.
3. A secret trick or clue that helps you solve a puzzle.
The keything to the riddle was hidden in the first line.
4. The most important part of a plan or idea.
The keything about our plan is to share the work fairly.