This is the 4917th most frequent Russian word.
ключе
"Ключе" is not a standalone word; it may be a form of "ключ," meaning "key" (literal or metaphorical), depending on context.
In this sentence, the word 'ключе' is used to mean 'key' in a figurative sense, signifying a solution or an answer to a problem.
Я нашёл ключе к этой загадке.
I found the key to this riddle.
Here, 'ключе' refers to a physical key used for locking or unlocking a door.
Ключе был спрятан под камнем возле дома.
The key was hidden under the stone near the house.
In this case, 'ключе' is used metaphorically to describe the central or focal aspect of something (stream of the region).