What's the "een" in Halloween?
Old English -istre, from Proto-Germanic *-istrijon, feminine agent suffix used as the equivalent of masculine -ere (see -er (1)). Also used in Middle English to form nouns of action (meaning "a person who ...") without regard for gender.
The genderless agent noun use apparently was a broader application of the original feminine suffix, beginning in the north of England, but linguists disagree over whether this indicates female domination of weaving and baking trades, as represented in surnames such as Webster, Baxter, Brewster, etc. (though spinster clearly represents a female ending). In Modern English, the suffix has been productive in forming derivative nouns (gamester, punster, etc.).
used to form nouns A person involved with, doing, or described by what is indicated: clubster/ gridster/ mobster/ oldster
[1000+; this Old English suffix, always common, has lately become very popular; for instance, forms like The Newtster, ''Newt Gingrich,'' are found]