The phrase "nasty crack" is often used to describe a hurtful or insulting comment. However, there are many other synonyms that can be used to convey similar meaning. Some alternatives include "cutting remark," "snide comment," "derogatory statement," "malicious quip," "snarky remark," "insulting jibe," "offensive barb," "mean-spirited jab," and "vitriolic feedback." These synonyms all indicate a negative and hurtful intention behind the words spoken. It is important to be mindful of the impact of our words on others and to strive to communicate in a respectful and kind manner.