rigid in WordNet English dictionary

1. fixed and unmoving
   "with eyes set in a fixed glassy stare"; "his bearded face already has a set hollow look"- Connor Cruise O'Brien; "a face rigid with pain"
   fixed  set  rigid 
   
2. incapable of adapting or changing to meet circumstances
   "a rigid disciplinarian"; "an inflexible law"; "an unbending will to dominate"
   inflexible  rigid  unbending 
   
3. designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure
   rigid 
   
4. incapable of or resistant to bending
   "a rigid strip of metal"; "a table made of rigid plastic"; "a palace guardsman stiff as a poker"; "stiff hair"; "a stiff neck"
   rigid  stiff 
   
5. incapable of compromise or flexibility
   rigid  strict