I don't know if this suggestion can be adapted to second grade, but I have used it with high school students. I hold a vocabulary scavenger hunt.
I create three or four poster boards with pictures I have cut from magazine and number the pictures for identification.. Each picture illustrates a new vacabulary word in some way. For example: a picture of an old house could illustrate a "verandah", a picture of hands playing the piano could illustrate "dexterity".
Next I type up lists of questions about the pictures. For example: Which picture is an example of "dexterity"? The students must look the word up in the dictionary, find the definition and identify the picture. The students learn to use the dictionary, and the pictures help set the vocabulary word in context. The students really enjoy this vocabulary game.