What's the difference between rigid and rigidulous?

Rigid

Definition:

(a.) Firm; stiff; unyielding; not pliant; not flexible.
(a.) Hence, not lax or indulgent; severe; inflexible; strict; as, a rigid father or master; rigid discipline; rigid criticism; a rigid sentence.

Example Sentences:

(1) By the 1860s, French designs were using larger front wheels and steel frames, which although lighter were more rigid, leading to its nickname of “boneshaker”.
(2) Diphenoxylate-induced hypoxia was the major problem and was associated with slow or fast respirations, hypotonia or rigidity, cardiac arrest, and in 3 cases cerebral edema and death.
(3) Pitlike surface structures seen in negatively stained whole cells and thin sections were correlated with periodically spaced perforations of the rigid sacculus.
(4) Rigidly fixing the pubic symphysis stiffened the model and resulted in principal stress patterns that did not reflect trabecular density or orientations as well as those of the deformable pubic symphysis model.
(5) The fracture can be treated arthroscopically by rigid internal fixation, while at the same time treating possible associated lesions.
(6) This study examined the extent to which normal learners identified as cognitively rigid could use alternate strategies when instructed to do so.
(7) In some patients stimulation can reduce rigidity and coactivation of muscles immediately or slowly over days or months.
(8) Major alleviation of the rigidity and bradykinesia with chronic oral l-dopa therapy was not accompanied by any change in the silent period.
(9) At clinically achievable concentrations, the combination of nafcillin plus gentamicin produced enhanced killing against 13 of 14 strains of enterococci and was synergistic (by very rigid criteria) against 10 of 14 strains.
(10) Low-temperature NMR studies indicate that 5 is more rigid than tamoxifen; interconversion between enantiomeric conformers is slow on the NMR time scale at -75 degrees C.
(11) Global 'abnormality', hunching (rigid arching of back), hindlimb abduction, forepaw myoclonus, stereotyped lateral head movements, backing, and immobility occurred significantly only in drug-treated rats.
(12) A study was made of twelve cases with uveitis, glaucoma and hyphema (UGH) caused by rigid intraocular posterior chamber implants.
(13) Eight alpha-helices behave as relatively rigid bodies and corner regions are more flexible, showing larger fluctuations.
(14) This modification allows for precision of movement, ease of repositioning, and adaptation of rigid skeletal stabilization of mobilized osseous segments in the chin.
(15) The pedicle screw systems were always the most rigid.
(16) Lactate dehydrogenase (LDH) levels and subunit isozyme patterns in cornea were monitored in 36 albino rabbits wearing thick, rigid, gas-permeable contact lenses for periods of 24 h, 2 and 7 days, and 1 and 3 months.
(17) The prevalence of sleep apnea, apnea index, duration of the longest episode of apnea, and penile rigidity were tabulated.
(18) During the last 21 months, 12 additional children have been managed with a more stringent protocol combining neck immobilization in a rigid cervical brace for 3 months and restriction of both contact and noncontact sports, together with a major emphasis on patient compliance.
(19) In the second placebo controlled experiment 150 mg im testosterone enanthate administration was associated with enhanced rigidity of NPT but with no effect on frequency or circumference change of NPT and no effect on frequency of REM.
(20) The whole isolator system included two rigid supply isolators, too.