ec·u·men·i·cism 
(ĕk′yə-mĕnĭ-sĭz′əm)
(ĕk′yə-mĕnĭ-sĭz′əm)n.
Ecumenism.
ec′u·meni·cist n.
- onto
- onto-
- on toes
- ontogenesis
- ontogenetic
- ontogenetically
- ontogenic
- ontogenically
- ontogeny
- ontological
- ontologically
- ontologist
- ontology
- on top
- on top of
- on top of the world
- on trial
- on/under pain of
- on/upon(one's) hands
- on/upon (one's) hands
- on/upon request
- on/upon the heels of
- on uppers
- onus
- on view