Why is it der Keeper?

Keeper ends in -er, and most nouns ending in -er are masculine: in a German dictionary, 86% of them take der.

All nouns ending in -er
Sense 1
der

Meaning

[1] Sport: The most defensive player of a sports team who is supposed to prevent the goals and is usually equipped with special rights

[1] Sport: defensivster Spieler einer Sportmannschaft, der Gegentore verhindern soll und meist mit Sonderrechten ausgestattet ist

[2] Short for: bartender

[2] kurz für: Barkeeper

Examples

[1] The keeper of the home team had to accept three goals conceded

[1] Die Keeper der Heimmannschaft musste drei Gegentore hinnehmen.

[2] The keeper mixes a Bloody Maryä

[2] Der Keeper mixt eine Bloody Mary.
More source examples (1)

These dictionary examples can include historical and less common uses.

[2] "After his striking appearance in the bar, the keeper later told him about dubious shops"

[2] „Nach seinem auffallenden Auftritt in der Bar hat ihm der Keeper später beim Absacker etwas von dubiosen Geschäften erzählt.“

Declension

1 Singular Plural
Nominativ der Keeper die Keeper
Genitiv des Keepers der Keeper
Dativ dem Keeper den Keepern
Akkusativ den Keeper die Keeper

Pronunciation

Dictionary entries include material from Wiktionary. Wiktionary