Etymology Borrowed from Yiddish כּשר (kosher), from Hebrew כָּשֵׁר (kashér).
1
Judaism Fit for use or consumption, in accordance with Jewish law (especially relating to food).
Only in New York can you find a good, kosher hamburger!
David's mother kept a kosher kitchen, with separate sets of dishes for meat and for dairy.
2 more examples
In order for a suit to be kosher, it cannot contain both wool and linen together.
Admirers of Israel’s kosher and nonkosher wines need the 2007 edition of “Rogov’s Guide to Israeli Wines” (Toby Press, $19.95).2007 January 14, Howard G. Goldberg, “A Tour of Israel, Bottle by Bottle”, in The New York Times, archived from the original on 30 Jun 2013:
2
Observant of the rules of kashrut (of a person or establishment).
"Are you kosher?" "No, I love to eat scallops."
"Is this restaurant kosher?" "No, we serve pork."
3
Broadly, Figuratively In accordance with standards or usual practice.
Etymology Borrowed from Yiddish כּשר (kosher), from Hebrew כָּשֵׁר (kashér).
1
In a kosher manner; in accordance with kashrut.
Just like eating halal is not a choice for our Muslim brothers and sisters, for us, eating kosher is not voluntary; it’s who we are and as necessary as the oxygen we need for sustenance.2020 August 20, Eliezer Brand, “ICE is forcing Muslims to eat pork. My fellow Orthodox Jews: This is our fight!”, in The Forward:
kosher
verb
Etymology Borrowed from Yiddish כּשר (kosher), from Hebrew כָּשֵׁר (kashér).
1
To kasher; to prepare (for example, meat) in conformity with the requirements of the Jewish law.