im·pugnBrE/ɪmˈpjuːn/NAmE/ɪmˈpjuːn/verbpresent simple - I / you / we / theyimpugnBrE/ɪmˈpjuːn/NAmE/ɪmˈpjuːn/present simple - he / she / itimpugnsBrE/ɪmˈpjuːnz/NAmE/ɪmˈpjuːnz/past simpleimpugnedBrE/ɪmˈpjuːnd/NAmE/ɪmˈpjuːnd/past participleimpugnedBrE/ɪmˈpjuːnd/NAmE/ɪmˈpjuːnd/ -ing formimpugningBrE/ɪmˈpjuːnɪŋ/NAmE/ɪmˈpjuːnɪŋ/~sth(formal) toexpressdoubtsaboutwhethersthisright, honest, etc.对…表示怀疑;质疑SYNchallenge