挠 ⇒
挠 náo, [撓], to scratch/to thwart/to yield
阻挠 zǔnáo, [阻撓], to thwart/to obstruct (sth)
挠痒 不屈不挠 bùqūbùnáo, [不屈不撓], unyielding/indomitable
挠头 náotóu, [撓頭], tricky/problematic/difficult/to scratch one's head (in puzzlement)
百折不挠 bǎizhébùnáo, [百折不撓], to keep on fighting in spite of all setbacks (idiom)/to be undaunted by repeated...