We do not currently know of any synonyms for ELAS.
The initialism ELAS is defined as:
ΕΛΑΣ (Εθνικός Λαϊκός Απελευθερωτικός Στρατός), the Greek People's Liberation Army the military arm of the left-wing National Liberation Front (ΕΑΜ) during the period of the Greek Resistance until February 1945.