Brexiter

Etymology tree
Ancient Greek Βρεττανός (Brettanós)
Proto-Indo-European *-h₂
Proto-Indo-European *-éh₂
Proto-Indo-European *-i-eh₂
Proto-Hellenic *-íā
Ancient Greek -ίᾱ (-íā)
Ancient Greek Βρεττανία (Brettanía)bor.
Latin Britannia
Anglo-Norman Britainebor.
Middle English Britayne
English Britain
Proto-Indo-European *h₁éǵʰ
Proto-Indo-European *-s
Proto-Indo-European *h₁éǵʰs
Proto-Italic *eks
Latin ex
Latin ex-
Proto-Indo-European *h₁ey-
Proto-Indo-European *h₁éyti
Proto-Italic *ejō
Proto-Italic *eō
Latin eō
Latin exeō
Proto-Indo-European *-tus
Proto-Italic *-tus
Latin -tus
Latin exitusder.
Middle English exit
English exit
blend
English Brexit
Proto-Indo-European *-yósder.
Proto-Italic *-āzijos
Latin -āriusnom.
Latin -āriusbor.
Proto-Germanic *-ārijaz
Proto-West Germanic *-ārī
Old English -ere
Middle English -ere
English -er
English Brexiter
From Brexit + -er.