名詞 nub:

1. a small lump or protuberance
   同義詞：nubble
2. a small piece
   同義詞：stub
3. the choicest or most essential or most vital part of some idea or experience
   同義詞：kernel, substance, core, center, essence, gist, heart, heart and soul, inwardness, marrow, meat, pith, sum, nitty-gritty

1. That's the nub of it.
   關鍵就在這里。
2. The nub of the problem is our poor export performance.
   問題的關鍵是我們出口貿易方面太差。

nub

n.（名詞）
A protuberance or knob.
凸起物或門把
A small lump.
小腫塊
The essence; the core:
要點；核心：
例句：
the nub of a story.
故事的要點

來源：
Variant of knub
knub的變體
probably from Low German knubbe
可能源自 低地德語 knubbe
from Middle Low German
源自 中古低地德語
variant of knobbe
knobbe的變體

【引伸】
nub.by
adj.（形容詞）