The antonyms for the phrase "be operation" can vary depending on the context. The term "operation" typically refers to a process or activity designed to achieve a specific goal. So, antonyms could include words like inactivity or idleness, which refer to a lack of action or movement towards a goal. Other possible antonyms might include words like failure, malfunction, or breakdown, which suggest that the intended operation did not succeed or was otherwise unsuccessful. Alternatively, some antonyms for "be operation" could be words like pause, delay or interruption, which imply a temporary halt in the process or activity.