Ordinal number (7)
(Other definitions for seventh that I've seen before include "This heaven is the most exalted state of happiness" , "after six" , "Interval just less than octave" , "Part of" , "This son of another is said to be a healer" .)
(Other definitions for eighth that I've seen before include "of an old Spanish piece" , "The Henry who fathered Elizabeth I" , "The last Henry or Edward?" , "Fractional amount of drug" , "Arm muscle" .)