What does "remainiac" mean?

One who opposes the idea of Brexit and wishes the United Kingdom to remain a member of the European Union.

How do you pronounce "remainiac"?

Pronounced //ɹɪˈmeɪ.niˌæk//.

/ɹɪˈmeɪ.niˌæk/ noun, slang

noun, slang ·Uncommon ·College level

Noun

1
One who opposes the idea of Brexit and wishes the United Kingdom to remain a member of the European Union. UK, neologism, slang
"Though no Remainiac, I will vote in."

"Though no Remainiac, I will vote in."

Blend of remain + maniac.