The term 'SALE RACK ABBR.' is an abbreviation for 'sale rack, ' which refers to a type of retail display where items are placed on racks and sold at discounted prices. The two crossword solutions for this term are 'IRREG' (5 letters) and 'IRR' (3 letters). 'IRREG' stands for 'IRREGULAR, ' which means that the items on the sale rack are not in perfect condition, while 'IRR' stands for 'IRREGULARLY, ' which means that the items on the sale rack are not always available at the same discounted price.