Inopportune is an adjective, which means not the right moment, inconvenient, or untimely. Some potential antonyms for inopportune include timely, appropriate, fortuitous, advantageous, or helpful. These words can be used to describe occasions that are well-timed or in the perfect moment. Another potential antonym is the word convenient, implying that something is easily accessible or well-suited for the situation. Other antonyms for inopportune may include propitious, lucky, advantageous, or fortuitous, all of which suggest that events or situations are favorable and occur at the right time. By using these antonyms, one can better articulate the specific meaning they wish to convey when describing events and timing.