opener

(noun) the first event in a series. Examples: "She played chopin for her opener." "The season's opener was a game against the yankees."

(noun) a person who unfastens or unwraps or opens. Synonyms: undoer, unfastener, untier. Example: "Children are talented undoers of their shoelaces."

(noun) a hand tool used for opening sealed containers (bottles or cans).