Essive case

In grammar, the essive case, or similaris case, (abbreviated ESS) is a grammatical case. The essive case on a noun can express it as a definite period of time during which something happens or during which a continuous action was completed. It can also denote a form as a temporary location, state of being, or character in which the subject was at a given time. The latter meaning is often described as the equivalent of the English phrase "as a __".