rigid

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”

incapable of compromise or flexibility

incapable of adapting or changing to meet circumstances

• “a rigid disciplinarian”
• “an inflexible law”
• “an unbending will to dominate”

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”

designating an airship or dirigible having a form maintained by a stiff unyielding frame or structure