Adjective ... 9 letters ... lasting for a very short time

There are a couple of adjectives that you can use to denote the meaning of - lasting for a very short time. However, here are some of them that have only 9 letters: transient, temporary, ephemeral, momentary, etc. So, each of these fits the description, and you can use either one of them to complete this assignment.

The answer to the question is the adjective temporary, it fits all the three description provided, it an adjective since it is word that describes other words, it means not permanent or lasting only for a period of time. Temporary has 9 letters in all.