The latter month of an option or futures contract. For example, when considering a three-month option at the time of purchase, months two and three could be thought of us deferred. In the second month of ownership, the third month could be considered deferred and so on.
The number of deferred months is part of what gives an option its time value, which is the difference between an option’s trading value and its intrinsic value. As the expiration date of an option nears, its time value diminishes.