A person (5)
(Other definitions for one that I've seen before include "doesn't count for much" , "Figure" , "Unity" , "Sole; identical" , "Identical; number" .)
'a person' is the definition.
(I know that Human is a type of person)
This is all the clue.
(Other definitions for human that I've seen before include "Characteristic of people" , "Like people" , "likely to err?" , "Mortal; compassionate" , "Fallible - person" .)
(Other definitions for each that I've seen before include "Everyone separately" , "Every one of a number" , "every one individually" , "Ache (anag.)" , "every individual" .)