The term is used for the fruit of any variety of pear which has an astringent taste and is difficult to swallow.
[1][2] One variety of choke pear is poire d'Angoisse, a variety of pear that was grown in Angoisse, a commune in the Arrondissement of Nontron in Dordogne, France, in the Middle Ages, which was hard, bad tasting, and almost impossible to eat raw.
[3][4] In the words of L'Académie française, the pear is "si âpre et si revèche au goût qu'on a de la peine à l'avaler" ("so harsh and crabbed of taste that one can only with difficulty swallow it").
[5] These qualities, and the common meaning of angoisse in French language ("anguish") apparently originated the French idiom avaler des poires d'angoisse ("swallow pears of Angoisse/anguish") meaning "to suffer great displeasures".
[6] Dalechamps has identified this with the species of pear that Pliny the Elder listed as "ampullaceum" in his Naturalis Historia.