柱【はしら】
pillar, post, support, prop, mainstay, counter for buddhas, gods, nobles, etc.
支柱【しちゅう】
prop, stay, support, brace, fulcrum
大黒柱【だいこくばしら】
central pillar (of a building), mainstay (e.g. of an economy), backbone (e.g. of a family), provider, main man
円柱【えんちゅう】
column, shaft, cylinder, round pillar (esp. in buildings)