- Orphean Adj.
- Orpheus Subst. Eigenn.
- Orphic Adj. Subst.
- Orphrey Subst. Verb Adj.
- Orpiment Subst. Adj.
- Orpine Subst. Adj.
- Orpington Subst. Eigenn. Adj.
- Orrery Subst. Adj.
- Orris Subst. Adj.
- Orsellinic Adj.
- Orthant Subst. Adj.
- Orthembadic Adj.
- Orthicon Subst. Adj.
- Orthite Subst. Adj.
- Orthitic Adj.
- Orthoacid Subst. Adj.
- Orthoamitosis Subst.
- Orthobiosis Subst.
- Orthocenter Subst. Adj.
- Orthocentral Adj.
- Orthocentric Adj.
- Orthocephalic Adj.
- Orthocephalous Adj.
- Orthocephaly Subst.
- Orthochromasia Subst.
- Orthochromatic Adj.
- Orthochromic Adj.
- Orthochronous Adj.
- Orthoclase Subst. Adj.
- Orthoclastic Adj.
- Orthocomplement Subst.
- Orthocomplementation Subst.
- Orthocomplemented Adj. Part. Perf.
- Orthocoupler Subst. Adj.
- Orthodentin Subst.
- Orthodiagram Subst. Adj.
- Orthodiagraph Subst. Adj.
- Orthodiagraphy Subst.
- Orthodontal Adj.
- Orthodontia Subst.
- Orthodontic Adj.
- Orthodontics Subst.
- Orthodontist Subst.
- Orthodontology Subst.
- Orthodox Adj. Eigenn.
- Orthodoxical Adj.
- Orthodoxically Adv.
- Orthodoxy Subst. Eigenn.
- Orthodrome Subst. Adj.
- Orthodromic Adj.
- Orthoepist Subst.
- Orthoepy Subst.
- Orthoferrite Subst. Adj.
- Orthogenesis Subst.
- Orthogenetic Adj.
- Orthogenetical Adj.
- Orthogenetically Adv.
- Orthogenic Adj.
- Orthogeosyncline Subst.
- Orthognathia Subst.