Why is it der Zeller?

Zeller 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] Austrian: celery

[1] österreichisch: Sellerie

Examples

[1] "Peel the cell tubers for the cell in the baking dough, cut 1 centimeter thick slices in approx.

[1] „Für den Zeller im Backteig die Zellerknollen schälen, in ca. 1 Zentimeter dicke Scheiben schneiden und im Wasser weich kochen.“

Declension

1 Singular Plural
Nominativ der Zeller —
Genitiv des Zellers —
Dativ dem Zeller —
Akkusativ den Zeller —

Dictionary entries include material from Wiktionary. Wiktionary