Synonyms for Illogical (same or very similar meaning)
WordNet sense 1 (inconsistent with reason or logic or common sense):
absurdWordNet sense 2 (lacking in correct logical relation):
unlogicalWordNet sense 3 (lacking orderly continuity):
confused, disconnected, disjointed, disordered, garbled, scattered, unconnectedWordNet sense 4 (without logical or meaningful connection):
incoherentFrom the ODE community, based on WordNetadd/edit