Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† būlē, ēs, f., = βουλή, the (Greek) council, the senate, Plin. Ep. 10, 116 (117), 1; 10, 81 (85), 1; 10, 110 (111), 1; 10, 112 (113), 1.