Wankel (n.) type of rotary internal combustion engine, 1961, from name of German engineer Felix Wankel (1902-1988).
wonky (adj.) "shaky, groggy, unstable," 1919, of unknown origin. German prefix wankel- has a similar sense. Perhaps from surviving dialectal words based on Old English wancol "shaky, tottering" (see wench (n.)).