Standby, reserve or extra. / (computing) That is intended as a backup. / Supporting, reinforcing; (music) of or related to accompaniment

The encroachment of ads, logos, and other types of corporate branding into public and traditionally non-commercial spaces, or the dissemination of corporate messages through methods or mediums not ...

Something, such as a glove or other pledge, thrown down as a challenge to combat (now usually figurative). / (obsolete) Something valuable deposited as a guarantee or pledge; security, ransom.

A bag (or other container) used to take home uneaten food from a restaurant meal. / A bag used to pick up the droppings of dogs in parks and public places.