/jon"ee/ , n. , pl. Johnnies for 1-3.
1. ( sometimes l.c. ) a familiar term of address for a man or boy.
2. ( sometimes l.c. ) Slang. a short, collarless gown that is fastened in back and is worn by hospital patients, persons being examined in a doctor's office, etc.
3. ( l.c. ) Slang. toilet; bathroom.
4. a male given name, form of John .
Also, Johnnie .
[ 1665-75; JOHN + -Y 2 ]