From Longman Dictionary of Contemporary Englishcluelessclue‧less /ˈkluːləs/ adjective informal NOT KNOWhaving no understanding or knowledge of something – used to show disapprovalclueless about Many teachers are clueless about the needs of immigrant students.
Examples from the Corpus
clueless• Joe's totally clueless.• But when it comes to road safety they are clueless.• The champagne may be warm, and the waitresses clueless.• Well, they were simply clueless and it could have been 9-0 again.• So I ended up at Safeway, utterly clueless as to where to find stockings.• I lie clueless in the cot until - until when?• I was clueless, of course, but it was an opportunity to strike up an amusing conversation.• He was followed by a very young and very clueless officer.• Polar Star is no exception; its lovely clueless opening soon snarls up in a mess of motives and half-finished characters.clueless about• Many teachers are clueless about the needs of immigrant students. 