Merriam-Webster's Advanced Learner's Dictionary:
eleven
elev·en /ɪˈlɛvən/ noun, pl -ens
1 [count] : the number 11
2 [count] : the eleventh in a set or series
• page eleven
• item/question number eleven
3 [noncount] : eleven o'clock
• I got home last night at eleven.
- eleven adj
• eleven turtles
- eleven pronoun
• Eleven (of them) were absent from the ceremony.
- elev·enth /ɪˈlɛvənɵ/ noun, pl -enths [count]
• one eleventh of the total
- eleventh adj
• the eleventh person in line
- eleventh adv
• He finished eleventh in the race.
