alterous UK /ˈɒltəɹəs/US /ˈɔltɚəs/ adjective2 •Pertaining to or characterized by an attraction to someone which is intermediate between platonic and romantic.These attractions might include, but are not limited to: sexual, romantic, platonic, aesthetic, and alterous attractions. — 2016 •Pertaining to or characterized by alterity (otherness, the entity in contrast to which an identity is constructed); other.