Synonyms for Musing (same or very similar meaning)
WordNet sense 1 (a calm lengthy intent consideration):
contemplation, reflection, rumination, thoughtfulness, reflexionWordNet sense 2 (persistently or morbidly thoughtful):
brooding, broody, contemplative, meditative, pensive, reflective, ruminative, ponderingWordNet sense 3 (exhibiting or characterized by careful thought):
thoughtfulFrom the ODE community, based on WordNetadd/edit