Usage: 5 forms in 10 verses
Form Translated As     In Verse(s)
πλανήσι for a delusion LXX.Neh.4.8
πλανήσεωσ addicted to a delusion LXX.Isa.19.14
of addiction to a delusion LXX.Jer.4.11
πλανήσει addiction to a delusion LXX.Isa.30.28
delusion LXX.Ezek.44.13LXX.Ezek.48.11
πλάνησισ an addiction to a delusion LXX.Isa.22.5LXX.Isa.30.28
πλάνησιν a delusion LXX.Isa.32.6
addicting delusion LXX.Isa.30.10

Liddell-Scott-Jones

πλάνησις (planēsis) a delusion G:N-F

πλάνησις-ησις, εως, ,

making to wander: dispersing, scattering, τῶν νεῶν [Refs 5th c.BC+]

__2 metaphorically, misleading, [Refs 2nd c.AD+]