What's the difference between eleven and undecennary?

Eleven

Definition:

(a.) Ten and one added; as, eleven men.
(n.) The sum of ten and one; eleven units or objects.
(n.) A symbol representing eleven units, as 11 or xi.
(n.) The eleven men selected to play on one side in a match, as the representatives of a club or a locality; as, the all-England eleven.

Example Sentences:

(1) The results of the oestrogen amplification test in eleven of the non-hyperprolactinaemic anovular patients were compared with the ovulatory response to 100 mg clomiphene given for 5 days.
(2) Eleven virus strains were isolated from ticks Hyalomma asiaticum asiaticum Schulce et Schlottke, 1929, and Hyalomma plumbeum plumbeum Panzer, 1796,collected in 1971-1974 in desert regions of the Uzbee S.S.R.
(3) Two hundred eleven adult emergency hand patients were prospectively tested over a 1-year period for drug and alcohol use.
(4) Eleven had hematological disorders, and 12 received steroids (sometimes with immunosuppressive or cytotoxic drugs).
(5) We performed a combined one-stage approach for the treatment of eighteen spastic subluxated or dislocated hips in eleven children who had cerebral palsy.
(6) Eleven per cent of the courses that responded provided no formal substance misuse training.
(7) Eleven (39%) had positive scans despite normal epicardial coronary arteries (7 patients) or a pretest risk of coronary disease less than or equal to 5% (4 patients).
(8) Eleven patients spontaneously passed the calculus, ten prior to delivery and one patient postpartum.
(9) Eleven tumors (23%) exhibited definite regression in the form of one or more segmental areas (defects) where the invasive component was replaced by mononuclear cell infiltrate and fibrosis.
(10) Eleven men with a less than 3% probability of coronary artery disease were used as a control population.
(11) Orthogonal field electrophoresis of the eleven strains still carrying pBR322 sequences revealed at least seven different integrating sites for the transforming DNA.
(12) Eleven rats were given twice-daily intraperitoneal injections of 20 mL of dialysis fluid containing 4.5% glucose for 6 weeks.
(13) Central nervous system toxoplasmosis was diagnosed in 12 immunosuppressed patients, eleven of whom had AIDS.
(14) Eleven women have died in India and dozens more are in hospital, with 20 listed as critically ill, after a state-run mass sterilisation campaign went horribly wrong.
(15) Eleven patients above the regression line had thrombosis in excess of fibrinolysis but the remaining 26 patients under the regression line had fibrinolysis in excess of thrombosis.
(16) Eleven effusions met one or more of three criteria commonly used to identify exudative effusions.
(17) Eleven patients had undergone replacement surgery in the knee joint area.
(18) Eleven months later and staff are still waiting to find out when – or if – the station will close and what exactly will replace it.
(19) Eleven were treated prior to clinical recurrence with 100% local control, no serious complications, and 86% long-term survival.
(20) A line in which 5-30% of the cells were lysable by anti-H-2Dd was cloned; all eleven clones had H-2Dd (13-69% lysable) demonstrating that H-2 modulates in vitro.