n. An accordion where the melody-side keyboard is limited to the notes of diatonic scales in a small number of keys.
the GNU version of the Collaborative International Dictionary of English
n. A kind of small reed organ; -- a portable form of the seraphine.
n. A music hall.
The Century Dictionary and Cyclopedia
n. A reed-organ or harmonium.
Word Usage
"The scene to be represented is a parlor furnished with sofa, chairs, carpet, pictures, table, and a melodeon, which is placed on the side of the stage."