All ' 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z ‘ first-order consumer (FURST OR-dur kun-SOO-mur) noun. in a food chain or food web, an organism that eats (consumes) a producer. First-order consumers are usually herbivores.