Where does this definition of as mad as a hatter come from?
This entry for as mad as a hatter is sourced from Main Dictionary, one of the dictionaries and corpora merged into Lughet.
Is as mad as a hatter a noun, verb, or something else?
In this entry, as mad as a hatter is tagged as 2adv..
What is Lughet?
Lughet is a free trilingual dictionary covering nearly five million entries across Uyghur, Chinese, and English, drawn from more than ten source dictionaries and corpora.