Darken
Webster's 1828 Dictionary
                        Darken
                    D'ARKEN, verb intransitive To grow dark or darker; also, to grow less white or clear.
Webster's 1828 Dictionary
                        Darkened
                    D'ARKENED, participle passive Deprived of light; obscured; rendered dim; made black; made ignorant.
Webster's 1828 Dictionary
                        Darkening
                    D'ARKENING, participle present tense Depriving of light; obscuring; making black or less white or clear; clouding.