Janeway lesions are nontender, small erythematous or haemorrhagic macules or nodules in the palms or soles, which are pathognomonic of infective endocarditis.
They are named after Theodore Caldwell Janeway (1872-1917), a professor of medicine with interests in cardiology and infectious disease -- and have nothing to do with Captain Janeway from the Star Trek: Voyager series. :-)