field: all of the horses in a particular horse race
set: a group of things of the same kind that belong together and are so used
geraniales: an order of plants of subclass Rosidae including geraniums and many other plants; see Euphorbiaceae; Geraniaceae; Rutaceae; Malpighiaceae; Simaroubaceae; Meliaceae; Zygophyllaceae; Tropaeolaceae