Sentence:  London's Kings Place, now one year old, established itself as a venue for imaginative programming, a <WSD>complement</WSD> to the evergreen Wigmore Hall. 
Meaning of the word marked with <WSD> tags:  Something which completes, something which combines with something else to make up a complete whole; loosely, something perceived to be a harmonious or desirable partner or addition. (from 19th c.)