ally

1. A person, group, or state (etc) which is associated with another for a common cause; one united to another by treaty or common purpose; a confederate.

   the two countries were allies in WWI

2. A person, group, concept (etc) which is associated with another as a helper; a supporter; an auxiliary.
3. Anything akin to something else by structure, etc.
4. A closely related species, usually within the same family.

   Gruiformes — cranes and allies

5. A relative; a kinsman.

1. To unite, or form a connection between, as between families by marriage, or between princes and states by treaty, league, or confederacy.
2. To connect or form a relation between by similitude, resemblance, friendship, or love.

1. A narrow street or passageway, especially one through the middle of a block giving access to the rear of lots or buildings.

   The parking lot to my friend's apartment building is in the alley.

2. The area between the outfielders.

   He hit one deep into the alley.

3. An establishment where bowling is played.
4. An elongated wooden strip of floor along which a bowling ball is rolled.
5. The extra area between the sidelines or tramlines on a tennis court that is used for doubles matches.
6. A walk or passage in a garden or park, bordered by rows of trees or bushes.
7. A passageway between rows of pews in a church.
8. (perspective drawing) Any passage having the entrance represented as wider than the exit, so as to give the appearance of length.
9. The space between two rows of compositors' stands in a printing office.

noun

A glass marble or taw.