{adv.} At a time several weeks or months in the past. - Used with "a". * /We had a good rain a while back, but we need more now./ * /Grandfather is well now, but a while back he was in the hospital for three weeks./ See: CRACK THE WHIP.
WHILE BACK
Meaning of WHILE BACK in English
Dictionary of English idioms . Словарь английских идиом. 2012