There are several synonyms for the phrase "cold chips" that may be used depending on the context. "Stale chips" or "old chips" may be appropriate if the chips have been sitting out for a while. "Chilly fries" could be used as an alternative for thicker cut chips that have gone cold, whereas "frosty potato wedges" may be more fitting for oven-baked chips that have become cold. For a more general term, "room temperature chips" might work, especially if there is no association specifically with warmth or coldness. Regardless of the synonym chosen, the underlying message remains the same- these are chips that are not hot nor fresh.