The word from the list that best fits the definition of "visualizing a game of 'tag' to remember the meaning of contagious" is "keywords." In this context, the phrase "tag" is being used as a keyword or visual aid to help remember the meaning of the word "contagious." Keywords are words or phrases that are used to help remember and recall specific pieces of information, and they are often chosen based on their association with the information being learned. In this case, the game of "tag" may have been chosen as a keyword because it helps to illustrate the concept of contagion, as the idea of one person "tagging" another can be used to help visualize the spread of an infection or disease. The use of keywords can be a useful technique for helping to remember and recall information, as it can help to create mental associations between the keyword and the concept being learned.