- 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.
- Orthocenter Subst. Adj.
- Orthocentral Adj.
- Orthocentric Adj.
- Orthocephalic Adj.
- Orthocephalous Adj.
- Orthochromatic Adj.
- Orthochromic Adj.
- Orthochronous Adj.
- Orthoclase Subst. Adj.
- Orthoclastic Adj.
- Orthocomplemented Adj. Part. Perf.
- Orthocoupler Subst. Adj.
- Orthodiagram Subst. Adj.
- Orthodiagraph Subst. Adj.
- Orthodontal Adj.
- Orthodontic Adj.
- Orthodox Adj. Eigenn.
- Orthodoxical Adj.
- Orthodrome Subst. Adj.
- Orthodromic Adj.
- Orthoferrite Subst. Adj.
- Orthogenetic Adj.
- Orthogenetical Adj.
- Orthogenic Adj.
- Orthognathic Adj.
- Orthognathous Adj.
- Orthognatic Adj.
- Orthogonal Adj. Subst.
- Orthogonalizable Adj.
- Orthogonalized Adj. Part. Perf.
- Orthograde Adj. Subst.
- Orthographic Adj.
- Orthographical Adj.
- Orthohydrogen Subst. Adj.
- Orthokeratology Subst. Adj.
- Ortholattice Subst. Adj.
- Orthology Subst. Adj.
- Orthometer Subst. Adj.
- Orthometric Adj.
- Orthomodular Adj.
- Orthomorphic Adj.
- Orthomyxovirus Subst. Adj.
- Orthonormal Adj.
- Orthonormality Subst. Adj.
- Orthonormalized Adj. Part. Perf.
- Orthooptic Adj.
- Orthooptical Adj.
- Orthopaedic Adj.
- Orthopantomogram Subst. Adj.
- Orthopantomograph Subst. Adj.