Dealer
Part of speech: noun
Definition: One who deals things, especially automobiles; a middleman. One who peddles illicit drugs, especially to teenagers. A particular type of stock broker or trader. The person who deals the cards in a card game.
Example sentence: My brother acquired his first gun when he was very young, from a recently-fled drug dealer's residence. Now, he lived in a rural orange-grove area, and he shot at coyotes who killed his animals and at drug runners who used the groves for transport. Sometimes he joked that he only shot what moved.
Principal
Part of speech: adjective
Definition: Primary; most important in a group.
Part of speech: noun
Definition: The money originally invested or loaned, on which basis interest and returns are calculatedThe principal administrator of a schoolOne who directs another (the agent) to act on one's behalfA company represented by a sales person
Example sentence: To smile at the jest which plants a thorn in another's breast is to become a principal in the mischief.