Its strange you say your parents were reluctant to speak the language, My Grandfather would get into serious trouble for speaking Scots Gaelic at school, and he also had a good command of Irish Gaelic, he would often use a word that sounded like

ALI - COO- SAH (ali as in ali baba, coo as in shoe, and sah as in bar) Ive no idea what it means but i suspect in maybe slang or profanity

can you shed any light?