Updated on 04/19/2018 a description of something in terms of the operations (procedures, actions, or processes) by which it could be observed and measured. For example, the operational definition of anxiety could be in terms of a test score, withdrawal from a situation, or activation of the sympathetic nervous system.

An operational definition in psychology is a detailed explanation of how a variable or concept is assessed or used in a specific study. It provides a precise, specific, and quantifiable description of a topic by outlining the steps or methods a researcher employs to define it.

The “operational” part means giving the meaning of something as it’s being used in a particular study. So in psychology, an operational definition means defining the variable as it exists in the present study (Source: Themantic Education).