The phrase "not mind" can be replaced with a variety of synonyms, depending on the context and tone desired. These include "don't care," "could do without," "it doesn't matter to me," "am indifferent to," "have no objection to," "not affected by," and "it's all the same to me." Each of these phrases expresses a level of disinterest or neutrality towards a particular situation or outcome. For example, "I don't mind if we go out to eat" could be replaced with "I'm indifferent to where we eat," indicating that the speaker has no preference or strong opinion on the matter.