set off

set off  {v.}

1. To decorate through contrast; balance by difference.

The bright colors of the birds were set off by the white snow.

A small gold pin set off her plain dark dress.

2. To balance; make somewhat equal.

Her great wealth, as he thought, set off her plain face.

3a. To begin to go.

They set off for the West in a covered wagon.

Compare: SET OUT.

3b. To cause to begin.

A letter from home set off an attack of homesickness.

An atomic explosion is created by setting off a chain reaction in the atom.

Compare: TOUCH OFF.

3c. To cause to explode.