底面

bottom / bottom side / bottom surface

(equivalent to 的 as possessive particle)

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

face / side / surface / aspect / top / classifier for objects with flat surfaces such as drums, mirrors, flags etc

variant of 麵|面[mian4]

flour / noodles / (of food) soft (not crunchy) / (slang) (of a person) ineffectual / spineless