n.
Pronunciation: ˌ käm-pl ə -( ˌ )men- ' ter- ə -t ē , -m ə n-, - ' ta-r ə -
Function: noun
Date: 1911
1 : the quality or state of being complementary
2 : the complementary relationship of theories explaining the nature of light or other quantized radiation in terms of both electromagnetic waves and particles