Definition
to squirrel away : to hide or store something for later
to squirrel away :(将来のために)蓄えておく、隠しておく
Example
I was able to squirrel away a nice sum of Japanese vocabulary over the summer thanks to language exchange.
この夏を通して、言語交流のおかげでたくさんの素敵な日本語を学べたよ。