Among (preposition)
Denotes a mingling or intermixing with distinct or separable objects. (See Usage Note at amidst)
"How can you speak with authority about their customs when you have never lived among them?"
Among (preposition)
Denotes a belonging of a person or a thing to a group.
"He is among the few who completely understand the subject."
Among (preposition)
Denotes a sharing of a common feature in a group.
"Lactose intolerance is common among people of Asian heritage."

Wiktionary

Among (preposition)
situated more or less centrally in relation to (several other things)
"you're among friends"
"flowers hidden among the roots of the trees"
Among (preposition)
being a member or members of (a larger set)
"snakes are among the animals most feared by man"
"a British woman was among the 54 victims of the disaster"
Among (preposition)
occurring in or shared by (some members of a group or community)
"members of the government bickered among themselves"
"a drop in tooth decay among children"
Among (preposition)
indicating a division, choice, or differentiation involving three or more participants
"the State Council would elect a temporary president from among its members"
"the old king called the three princesses to divide his kingdom among them"

Oxford Dictionary

Among (preposition)
Mixed or mingled; surrounded by.
Among (preposition)
Conjoined, or associated with, or making part of the number of; in the number or class of.
Among (preposition)
Expressing a relation of dispersion, distribution, etc.; also, a relation of reciprocal action.

Webster Dictionary