to block up (a road, pipe etc) / to stop up (a hole) / (fig.) (of a person) choked up with anxiety or stress / wall (literary) / (classifier for walls)
堵
=
土
+
者
:
Louis XIV (者) built castle walls (堵) out of dirt (土) in the space station (Ø3), but now since the passage through the space station is blocked (堵), every morning when Doggy Dog (du) commutes to work he gets stuck in a traffic jam (堵) caused by the castle walls.
塞
=
基
+
宀
:
Socrates (s) wanted to get rid of his graduation cap (宀) and threw it in the elevator's toilet (e4), but now it is clogged (塞). He'll have to dig up the foundation (基) to clear the pipes.