1. The underlying support or justification of something
   "Scientific evidence forms the underpinning of the theory"
    
2. (construction) a structure that supports or strengthens an existing foundation
   "The old building required underpinning to prevent further settling"

1. Support from beneath
   "The foundation underpins the entire structure"
    
2. Support or confirm with evidence or authority
   "The new findings underpin our initial hypothesis";
   - corroborate, bear out, support

Derived forms: underpinnings

Type of: agree, check, correspond, fit, gibe, hold, hold up, jibe, marry, marry up, match, square, support, sustain, tally

Encyclopedia: Underpinning