透底

to disclose inside information / to divulge secret details

to penetrate / to pass through / thoroughly / completely / transparent / to appear / to show

(bound form) to penetrate; to seep through / to tell secretly; to leak / thoroughly; through and through / to appear; to show

(equivalent to 的 as possessive particle)

background / bottom / base / end (of the month, year etc) / remnants / (math.) radix / base

(of a body of water) clear enough to see the bottom / limpid