An Etymological Dictionary of the German Language/Annotated/haft
haft, adjective suffix, as in schmerzhaft, lebhaft, &c.; properly an independent adjective, ‘combined with,’ which was used as a suffix even in Middle High German and Old High German; in Gothic audahafts, ‘overwhelmed with happiness, supremely happy.’ This suffix is usually identified with the adjective hafta-, Latin captus, discussed under Haft (2.). It might also be derived from the root hab, ‘to have,’ Latin habere; the meaning supports the latter supposition.