The antonyms for "am service" are "pm service" and "night service." "AM" denotes the time in the morning, typically between midnight and noon, and refers to services that take place during this time. Therefore, the opposite of AM service would be a service that takes place in the afternoon or at night, which is known as PM or night service, respectively. These services are often found in industries such as transportation, healthcare, and hospitality, where people need 24-hour attention and care. Overall, understanding the antonyms for "am service" is important, as it can provide a clear idea of the different times of the day when services are offered.