fundament

noun

1. the fundamental assumptions from which something is begun or developed or calculated or explained

Similar word(s): base, basis, cornerstone, foundation, groundwork

Definition categories: thought, assumption, supposal, supposition

2. the fleshy part of the human body that you sit on

Similar word(s): backside, behind, bottom, bum, buns, butt, buttocks, can, derriere, fanny, hindquarters, keister, nates, posterior, prat, rear, rump, seat, stern, tail, tush

Definition categories: body

3. lowest support of a structure

Similar word(s): base, foot, foundation, groundwork, substructure, understructure

Definition categories: man–made, support