lovebug

Short definition from Wiktionary

Noun

1. 1
   An insect, the honeymoon fly (Plecia nearctica, family Biblionidae), native to Central America and the southeastern United States.
2. 2
   An insect native to subtropical regions of south-eastern China, Taiwan, and Japan (Plecia longiforceps).
3. 3
   A person who is in love; a sweetheart.