Can be used as all parts of speech, except for a conjunction, proper noun, and preposition: a step-dave is an angry, critical, over-bearing, overzealous step-parent, that has a skewed view of the world. Step-Dave can be used as an insult, or just to replace words in a sentence.
(Someone just spilled coffee all over your sofa) "Wow, your such a Step-Dave!" Or, "STEP-DAVE! I spilled coffee all over your sofa." "Stop Step-Daving all over my sofa, you Step-Dave!"