The antonyms for the word "up grade" are "downgrade," "demote," "lower," or "declassify." These words refer to a decrease in status, quality, or value, rather than an increase. A downgrade often means stepping down from a higher position or rank, while a demotion refers to a reduction in job responsibilities or authority. Lowering can refer to a reduction in the strength, price or value of a product, while declassifying can refer to the loss of confidentiality or security clearance. Understanding the different antonyms of "up grade" can help people differentiate between positive and negative changes in situations.