兜底

to reveal / to expose

pocket / bag / to wrap up or hold in a bag / to move in a circle / to canvas or solicit / to take responsibility for / to disclose in detail / combat armor (old)

old variant of 兜[dou1]

(equivalent to 的 as possessive particle)

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