lovebird

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of various small Old World parrots, especially of the genus Agapornis, often kept as cage birds and noted for the apparent affection between mates.
2. n. Informal A couple who are openly affectionate or demonstrative with each other, especially in public.

Century Dictionary and Cyclopedia

1. n. A little parrot or parrakeet, remarkable for the affection it shows for its mate. Many species of different genera have this trait. They are all of diminutive size. The American love-birds belong to the genus Psittacula, and some of them have also been called Agapornis. They are such as P. passerina, with several related species or varieties, and P. purpurata. The true love-birds belong to the restricted genus Agapornis, all of which are African. They are such as A. cana, A. pullaria, and A. swinderniana. (See cut under Agapornis.) The most familiar of these is A. pullaria, scarcely 7 inches long, bright-green with a rose-red face and throat, coralline bill, gray feet, and short rounded tail, which when spread shows a red field bordered with a subterminal bar of black. It thrives on canary-seed, and makes a charming pet. Another group of love-birds inhabits the East Indian archipelago, New Guinea, and Australia, and represents divisions of the genus Psittacula (in a large sense) called Cyclopsitta and Psittinus. Such are C. diophthalma of the Aru Islands, P. malaccensis, etc. The most diminutive of parrots, Nasiterna pygmæa, belongs to the same group as the last. Also love-parrakeet, love-parrot.

Wiktionary

1. n. Any small parrot from one of the nine species within the genus Agapornis (Greek: αγάπη agápē 'love'; όρνις órnis 'bird'), sometimes they are kept as cage birds, noted for their affection towards each other.
2. n. metaphorical, usually in the plural (One of the persons of ) an openly affectionate couple.

GNU Webster's 1913

1. n. (Zoöl.) any one of several species of small, short-tailed parrots, or parrakeets, of the genus Agapornis, and allied genera. They are mostly from Africa. Some species are often kept as cage birds, and are celebrated for the affection which they show for their mates.
2. n. A small Australian parakeet (Melopsittacus undulatus) usually light green with black and yellow markings in the wild but bred in many colors; also called the budgie.
3. n. small African parrot noted for showing affection for their mates.

WordNet 3.0

1. n. small Australian parakeet usually light green with black and yellow markings in the wild but bred in many colors
2. n. small African parrot noted for showing affection for their mates