Definition of reinstate for English Language Learners : to put (someone) back in a job or position that had been taken away : to begin using or dealing with (a law, policy, system, etc.) again
Detailed Synonyms for period of time in English. period of time: period of time [the ~] noun. the period of time the term; the period of time; the period; the space of time; the time; the space term [the ~] noun.
An era is a commonly used word for a long period of time. When used in science, for example geology, an era denotes a clearly defined period of time of arbitrary but well-defined length, such as for example the Mesozoic Era from 252 Maâ66 Ma, delimited by a start event and an end event.