a piece of research, a study, investigation

to research, to study

(chiefly women's speech) first person singular pronoun: I, me

deep, profound

staying up late

uncertain; unreliable; inauthentic

impossible

impossibility, that which is impossible

incomprehensible, mysterious, baffling / insoluble, insolvable, inexplainable, inexplicable

incomprehensibility, mysteriousness / insolubility, inexplicability