1. The fundamental assumptions from which something is begun, developed, calculated or explained
   "These principles form the fundament of modern physics";
   - basis, base, foundation, groundwork, cornerstone
    
2. Lowest support of a structure
   "it was built on a fundament of solid rock";
   - foundation, base, foot, groundwork, substructure, understructure
    
3. [informal] The fleshy part of the human body that you sit on
   "He landed hard on his fundament";
   - buttocks, nates [informal, technical], butt [N. Amer, informal], backside [informal], bum [Brit, informal], buns [N. Amer, informal], can [N. Amer, informal], hindquarters [informal], hind end [informal], posterior [informal], rear [informal], rear end [informal], rump [informal], stern [informal], seat [informal], tail [N. Amer, informal], tail end [informal], tooshie [informal], tush [N. Amer, informal], bottom [informal], behind [informal], derriere [informal], patootie [US, informal], botty [informal], duff [N. Amer, informal], bahookie [UK, dialect, informal], booty [N. Amer, informal], heinie [US, informal], tushy [N. Amer, informal], derrière [informal]

Derived forms: fundaments

Type of: assumption, body part, support, supposal, supposition

Part of: body, construction, explanation, structure, torso, trunk

Encyclopedia: Fundament