face / side / surface / aspect / top / classifier for objects with flat surfaces such as drums, mirrors, flags etc
面
=
丆
+
囬
:
Mnemonic symbol: a spray flask with one of these liquids which make a surface super slippery.
In the anthill's bathroom (an4), Marilyn Monroe (mi) wants to set up a wind wheel (丆) on top of a closet (囬). Just as she tries to fix it she slips and falls down, the wind wheel crashing on the floor. She didn't notice that somebody used a can of non-stick coating (面) on the closet's surfaces (面).