The cruciverbalist within

For whatever reason, I can never keep these three words straight:

Dada: a cultural movement that began in Zürich, Switzerland, during World War I and peaked from 1916 to 1922.

Dado: a slot or trench cut into the surface of a piece of machinable material, usually wood.

Dido: according to ancient Greek and Roman sources, the founder and first Queen of Carthage (in modern-day Tunisia). She is best known from the account given by the Roman poet Virgil in his Aeneid.