pillar /ˈpɪlɚ/ noun
plural pillars
plural pillars
Learner's definition of PILLAR
: a large post that helps to hold up something (such as a roof)
: someone who is an important member of a group + of
: a basic fact, idea, or principle of something + of
: something that rises into the air in a tall, thin shape

from pillar to post

chiefly British
: from one place or one situation to another

pillar of strength

: someone or something that gives support or help during difficult times