難関 (なんかん)barrier; obstacle; difficulty

難関, its kanji, and other words that share them.Open this graph

Kanji in 難関

難民なんみんrefugee; displaced person
困難こんなんdifficulty; hardship
避難ひなんtaking refuge; finding shelter
非難ひなんcriticism; blame
避難民ひなんみんevacuees; displaced persons
難しいむずかしいdifficult; hard
難色なんしょくdisapproval
難問なんもんperplexity; difficult question
機関きかんengine
関係かんけいrelation; relationship
関係者かんけいしゃperson concerned; people involved (in an event)
関心かんしんconcern; interest
関連かんれんrelation; connection
関せきbarrier; gate
関税かんぜいtariff (import tax); duty
関西かんさいKansai; region consisting of Osaka, Kobe, Kyoto and surrounding prefectures

See how 難関 connects to the rest of Japanese.