Downtime refers to the time during which a system or machinery is not operational or can be utilized for other purposes. It is essential to have alternative phrases to avoid repetition while communicating about the downtime of a process or system. Some of the synonyms for downtime include "idle time," "inactive period," "maintenance time," "unproductive time," "slow time," and "off-peak period." Other phrases that can be used in place of downtime include "delay," "interruption," "break," "period of rest," "intermission," "pause," and "hiatus." Using these terms instead of downtime can help vary your language and ensure that your message is conveyed effectively and without losing your reader's attention.