'Undergird' definitions:

Definition of 'undergird'

From: WordNet
verb
Lend moral support to
verb
Make secure underneath; "undergird the ship" [syn: undergird, brace up]

Definition of 'Undergird'

From: GCIDE
  • Undergird \Un`der*gird"\, v. t. To bind below; to gird round the bottom. [1913 Webster]
  • They used helps, undergirding the ship. --Acts xxvii. 17. [1913 Webster]