A quick, fun and engaging activity to have students learn and interact with vocabulary is a game called Flash Vocabulary. A teacher may use this strategy as part of an anticipatory set, or treated as an enacted-on-the-spot strategy when student engagement is running low.
In this game, students are paired up. Using a document camera or overhead projector, the teacher projects the vocabulary words onto a screen or wall. Alternatively, the teacher can also just write the words and cover them up as well with a large post-it / poster.
Next, in pairs, one student has their back to the vocabulary word and one student is facing the vocabulary (the direction of the screen). As the teacher unveils/flashes the vocabulary, the students facing the screen have the job of describing or defining each of the vocabulary words WITHOUT using the vocabulary words. As you can guess, students with their backs to the screen have the job to correctly identify the vocabulary word.
To step it up, teachers may throw down a list of words (new and old). The goal here for the students is to be the first pair to correctly identify all the vocabulary words.
During this game, students are thinking and interacting with their vocabulary and most, if not all, students are engaged. The game can last 3-5 minutes, depending on number of vocabulary words.
Bottom-line: Flash Vocabulary is an effective (and quick) strategy to boost student engagement and increase student interactions with new and old vocabulary.