一无所知

not knowing anything at all (idiom); completely ignorant / without an inkling

one / single / a (article) / as soon as / entire; whole; all; throughout / "one" radical in Chinese characters (Kangxi radical 1) / also pr. [yao1] for greater clarity when spelling out numbers digit by digit

not to have / no / none / not / to lack / un- / -less

actually / place / classifier for houses, small buildings, institutions etc / that which / particle introducing a relative clause or passive / CL:個|个[ge4]

known / what one knows

to know / to be aware