Noun
1. a fundamental principle or practice;
"science eroded the pillars of superstition"2. anything tall and thin approximating the shape of a column or tower;
"the test tube held a column of white powder""a tower of dust rose above the horizon""a thin pillar of smoke betrayed their campsite"3. a prominent supporter;
"he is a pillar of the community"4. a vertical structure standing alone and not supporting anything (as a monument or a column of air)
5. (architeture) a tall cylindrical vertical upright and used to support a structure