decoct
Concise Oxford English Dictionary © 2008 Oxford University Press:
decoct /dɪˈkɒkt/
▶verb archaic extract the essence from (something) by heating or boiling it.
– origin ME: from L. decoct-, decoquere ‘boil down’, from de- ‘down’ + coquere ‘cook’.
'decoct' also found in these Oxford entries:

