Meaning : The first event in a series.
Example :
She played Chopin for her opener.
The season's opener was a game against the Yankees.
Meaning : A person who unfastens or unwraps or opens.
Example :
Children are talented undoers of their shoelaces.
Synonyms : undoer, unfastener, untier
Meaning : A hand tool used for opening sealed containers (bottles or cans).