civ·i·lize
ˈsivəˌlīz
verb
past tense: civilized; past participle: civilized
bring (a place or people) to a stage of social, cultural, and moral development considered to be more advanced.
"a civilized society"
synonyms: enlighten, edify, improve, educate, instruct, refine, cultivate, polish, socialize, humanize
"they were trying to civilize people who strongly resented the intrusion"
..
polite and well-mannered.
adjective: civilized; adjective: civilised
"such an affront to civilized behavior will no longer be tolerated"
synonyms: polite, courteous, well mannered, civil, gentlemanly, ladylike, mannerly;
...According to the definitions above we have two possible answers, depending on definition. Regarding the first definition:
ad·vanced
ədˈvanst
- adjective
far on or ahead in development or progress.
"negotiations are at an advanced stage"
synonyms: state-of-the-art, new, modern, developed, cutting-edge, leading-edge, up-to-date, up-to-the-minute, the newest, the latest; More
- new and not yet generally accepted.
"his advanced views made him unpopular"
Let's ignore the second definition since civilization is generally popular enough. Progress...
prog·ress
1.
noun
ˈpräɡres/
forward or onward movement toward a destination.
"the darkness did not stop my progress"
synonyms: forward movement, advance, going, progression, headway, passage
"boulders made progress difficult"
verb
prəˈɡres/
move forward or onward in space or time.
"as the century progressed, the quality of telescopes improved"
synonyms: go, make one's way, move, move forward, go forward, proceed, advance, go on, continue, make headway, work one's way
"they progressed slowly down the road"
The second definition gives us "civilization is that which is further in time" which is overly broad and tautological.
The first definition is subjective. We require a destination. I must ask, what OP considered the the ideal social, cultural, or moral environment to aspire after? People holding these qualities akin to this ideal will therefore be civilized.
Regarding the second definition "polite and well mannered."
po·lite
pəˈlīt
adjective
having or showing behavior that is respectful and considerate of other people.
...
re·spect·ful
rəˈspek(t)fəl/
adjective
feeling or showing deference and respect.
...
re·spect
rəˈspekt
noun
1.
a feeling of deep admiration for someone or something elicited by their abilities, qualities, or achievements.
...
ad·mi·ra·tion
ˌadməˈrāSH(ə)n/
noun
respect and warm approval.
...
con·sid·er·ate
kənˈsidərət
adjective
careful not to cause inconvenience or hurt to others.
...
def·er·ence
ˈdef(ə)rəns
noun
humble submission and respect.
...
In conclusion, a civilized person:
I know an animal that generally fits this description.