antediluvian (adjective) antediluvian: out-of-date; prehistoric
Sinonime: be at cross purposes, be bewildered, be confused, be perplexed, confound, confuse, fail, get signals crossed, get signals mixed, get wrong, get wrong impression, misapply, misapprehend, miscalculate, miscomprehend, misconstrue, misinterpret, misjudge, misknow, misread, misreckon, miss the point, miss*, mistake, not register, take amiss, take wrongly
Antonime: modern,
new,
up-to-date,
young