词汇 means vocabulary or words and phrases.
In traditional characters (I noticed today) that would be: 詞彙 and 彙 is a word for hedgehog (刺猬）。(詞彙: word hedgehog)
Did the ancient Chinese gather hedgehogs? Did 彙 mean "gather" first and "hedgehog" later?
How are "hedgehog" and "gather" related? As far as I know, hedgehogs are not gregarious little beasts, too spiky!
(I know the British used to catch hedgehogs, cover them in mud and bake them in a fire. Probably still do 'up North'. Mmmm, delicious!)