Your solution of the etymology of this word, as coming from
_Coney_-borough, is no doubt correct: but I apprehend the last syllable has
a more specific derivation. On the opposite sides of the Lough of Belfast,
there are two localities in which this old English word is preserved. This
district was, as you are aware, colonised by English settlers about 1590
A.D., when large grants were made to Sir Arthur Chichester, ancestor of the
present Marquis of Donegal. At Carrickfergus, on the north side of the bay,
there is a spot called the _Connyberry_, which is a corruption of
"Coneyborough;" but on the opposite side, at Holyward, there is a populous
rabbit-warren, known as the "Kinnegar;" which I take to be the _conynger_
or _coningeria_ about which your correspondent asks.