functionality

toimivuus The ability to perform a task or function; that set of functions that something is able or equipped to perform.
puhekieltä In United States trademark law, the tendency of a product design to serve a function other than identification of the product, preventing that design from being protected as a trademark.
puhekieltä The presence of a functional group.

http://www.sigmaaldrich.com/etc/medialib/docs/Aldrich/Acta/al_acta_30_01.pdf Aldrichimica Acta Volume 30 No 4 (pdf) from http://www.sigmaaldrich.com/chemistry/chemical-synthesis/learning-center/aldrichimica-acta.html Sigma-Aldrich

The vinyldiazomethanes that have been commonly used in our studies contain an electron-withdrawing group adjacent to the diazo functionality.