26,102words currently have published synonym-style alternatives
90,593searchable synonym connections
350,924published thesaurus relationships of every type
Start with the meaning
Harmonium
A musical instrument, resembling a small organ and especially designed for church music, in which the tones are produced by forcing air by means of a bellows so as to cause the vibration of free metallic reeds. It is now made with one or two keyboards, and has pedals and stops.
An instrument or medium by which some important action is performed, or an important end accomplished; as, legislatures, courts, armies, taxgatherers…
oewn 202368% interchangeable
Open English WordNet places these words in at least one shared synset. They share a lexicalised sense, but context, register and collocation should still be checked before substitution.