Out-of-line is a phrase that is used to describe something or someone that is inappropriate or behaving in a disturbing manner. To express this sentiment in different ways, there are several synonyms that can be used. Some of the words synonymous with out-of-line are improper, unacceptable, indelicate, impolite, discourteous, and inappropriate. If someone is being out-of-line, they are displaying behavior that goes beyond the confines of what is considered acceptable. Synonyms for the phrase often convey a sense of disapproval and suggest that the person's actions are not appropriate or welcome. No matter which synonym is used, it is clear that being out-of-line is not something that is encouraged or valued in our society.