And there are tricks to increase our stash of control. A new study shows you can practice it, as one would practice any new skill.
这个网页上给出的释义:
[重难点词汇、短语](点击展开/收起)
stash : n. 藏匿物
显然是不通的。
查一下词典:
新世纪英汉大词典:
stash¹/stæʃ/n.
1.<非正式>(hoard)藏匿处
<幽默>(stored material)藏匿物
A large stash of drugs has been found aboard the yacht.
在游艇上发现了一个很大的毒品藏匿室。
a stash of letters
封存的信件
2.<俚>(personal supply)私人藏匿的毒品
stash²/stæʃ/vt.
<非正式>秘密存放;藏匿
牛津·外研社英汉汉英词典
stash | BrE staʃ, AmE stæʃ | informal
A. transitive verb
藏匿 ‹heirlooms, stolen goods›
▸ to stash money under the floorboards
把钱藏在地板下面
B. noun
藏匿物
▸ they found a stash of heroin in the car
他们发现了藏在车里的一批海洛因
COD9 - Concise Oxford English-Chinese Dictionary 9th
stash
/stæʃ/ v. & n. colloq.[口]
v. tr. (often foll. by 常后跟 away)
1conceal; put in a safe or hidden place隐藏,藏匿
2hoard, stow, store储藏,贮藏,贮备
n.
1a hiding place or hideout隐藏处,藏匿处
2a thing hidden; a cache隐藏物;贮藏物
[18th c.: origin unknown]
牛津高阶双解(第四版)
stash
n
infmlesp US
thing that is stored secretly 隐藏的东西。
place where sth is hidden; hiding-place 隐藏处:
a secret stash of stolen jewels隐藏偷来的珠宝的地方。
LDOCE6,OALD10,OED的解释最为准确:

A quantity of an illegal drug, especially one kept for personal use.
可见,上文中的意思更强调的是数量而不是藏匿,后者主要是为增加幽默效果。这样看来,“贮藏物”一项是最为准确的。