Of of the gradable (synthetic) adjectives (adjective that have suffix of "-er" or "-est") is mean > meaner > meanest). Now looking at the dictionary, shows 7 meanings for this adjective!
Adjective: mean (meaner,meanest) meen
1) (statistics) approximating the statistical norm, average or expected value "the mean annual rainfall"; -
2) Characterized by malice
"in a mean mood"; -
3) Having or showing an ignoble lack of honour or morality
"taking a mean advantage"; "chok'd with ambition of the meaner sort"; base, meanspirited
"famous for a mean backhand"
5) Marked by poverty befitting a beggar
"a mean hut"; beggarly
6) (used of persons or behaviour) characterized by or indicative of lack of generosity
"a mean person"; mingy, miserly, tight
7) (used of sums of money) so small in amount as to deserve contempt beggarly
8) Of no value or worth
"I was caught in the mean traffic";bastardly
My question is what is the common meaning among them that normally get the grades of comparative and superlative, because for the moment it doesn't make sense to me that the 1st meaning for example (statistics) can have grades, so I guess that just one or few of them normally get comparison or superlativeness.