A complementary good or service is something used or provided in combination with another good or service. The word complementary means combining to enhance or emphasize each other's qualities.

Complementary and alternative medicines are all over lately: herbal supplements, massage, essential oils, and more. You might love how some of these therapies make you feel, but are they safe for your ...

dismiss an opposition to the registration of WATERFORD STELLENBOSCH for wine. The board held that since the goods covered by the proposed registration were complementary to glassware products covered ...