Antonyms for "act with regard to" vary depending on the context in which it is used. If it pertains to a legal framework, antonyms would include neglect, ignore, or disobey. For instance, if someone disobeyed or ignored a court order, they would not have acted with regard to it. In a social setting, antonyms would mean disregard, disrespect, or dismiss. To act without regard could indicate a lack of consideration or respect for other people's feelings or well-being. In a personal context, one might use antonyms like forget, overlook, or be careless. The antonyms convey the opposite of acting with regard to something, indicating a lack of attention or intention towards it.