rigid

Main Entry:	rig·id 
Pronunciation:	'ri-j&d
Function:	adjective
Etymology:	Middle English rigide, from Latin rigidus, from rigEre to be stiff
1 a : deficient in or devoid of flexibility <rigid price controls> <a rigid bar of metal> b : appearing stiff and unyielding <his face rigid with pain>
2 a : inflexibly set in opinion b : strictly observed <adheres to a rigid schedule>
3 : firmly inflexible rather than lax or indulgent <a rigid disciplinarian>
4 : precise and accurate in procedure <rigid control of the manufacturing process>