or fen nightingale, subs. phr. (common).—A frog. [The county is scored with canals and dykes; the allusion is to the natural preponderance of the croaking of frogs over the singing of nightingales.] Cf. CAMBRIDGE OAK and CAPE NIGHTINGALE.
1875. Chambers’s Journal, No. 581, p. 107, col. 2. The male of the eatable frog is distinguished … by … a pouch…. These pouches increase the volume of the croak, and render it so powerful that the possessors have, from the county in which they are particularly plentiful, received the nickname of CAMBRIDGESHIRE NIGHTINGALES.
