אז"ר is an abbreviation for אלכסנדר זיסקינד רבינוביץ, a jewish writer. An Israeli village is named after him: כפר אז"ר. In the IDF jargon, אז"ר means: אוייב זרק רימון (enemy threw a grenade), a battlecry for when a force is being attacked with grenades.

http://www.kizur.co.il/search_word.php?abbr=%D7%90%D7%96%22%D7%A8&searchby=abbr&m=1 On this site you can find the expansions of abbreviations. I don't know whether one of the two answers they give fits your query or not.