pseudo-axis
/ˈs(j)uːdəʊˌaksɪs/noun
1 Botany = sympodium.
2 Crystallography. An axis with reference to which a structure displays pseudosymmetry.
Origin
Late 19th century; earliest use found in Alfred Bennett (1833–1902), botanist and publisher. From pseudo- + axis, in sense 1 after German †Scheinaxe.