The term comes from a Gaelic word for a parliament or congress in common use during the Lordship of the Isles. Despite this, many also believe the word originates from Brythonic (or more precisely, Welsh). The same term can be seen in eisteddFOD < MOD. However, the Welsh word is simply is a form of the verb 'to be'; 'yn fod yn eistedd' simply means 'being seated', c.f. "session". The term in Scotland may arise from Old English 'gemot' (cf. witenagemot).
A Mod largely takes the form of formal competitions. Choral events (in Gaelic, both solo and choirs), and traditional music including fiddle, bagpipe and folk groups dominate. Spoken word events include children and adult's poetry reading, storytelling and Bible reading, and categories such as Ancient Folk Tale or Humorous Monologue. Children can also present an original drama, and there are competitions in written literature.
Unlike the National Mod, local mods usually only last a day or two. They attract a much smaller crowd and the only notable social event is the winners' ceilidh. As there are fewer competitions than in the National, this ceilidh is often more like a traditional ceilidh with dancing and guest singers between the winners' performances.