Wrong meaning for empirical.

[John Law]

Error in definition of word. Other dictionaries make no such inference as 'relying on medical quackery' Instead they say just the opposite eg 'Guided by practical experience and not theory, especially in medicine'.

Your entry is
empirical ~ adj rare
 1. derived from experiment and observation rather than theory
an empirical basis for an ethical theory; empirical laws; empirical data; an empirical treatment of a disease about which little is known
 2. relying on medical quackery
empiric treatment