1. : extremely ignorant
a know-nothing blunderer
the Know-Nothing party … proposed the political proscription of Roman Catholics — W.L.Sperry
the know-nothing anti-intellectualism that parades … as anti-Communism — Stringfellow Barr
1. : one that knows little or nothing : ignoramus
2. usually capitalized K&N [so called from the fact that some members of the organization replied “I don't know” to any questions that were asked them about it] : a member of a 19th century short-lived secret American political organization prominent in the decade before the Civil War and hostile to the political influence of recent immigrants and Roman Catholics
3. : agnostic
4. : an exponent or adherent of 20th century political know-nothingism
counting on the know-nothings … to exploit the present atmosphere of uncertainty and insecurity — Norman Cousins
assaults upon intellectuals by political know-nothings — Richard Robbins
Useful english dictionary. 2012.