Al·ly v. t. [imp. & p. p. Allied p. pr. & vb. n. Allying.]
1. To unite, or form a connection between, as between families by marriage, or between princes and states by treaty, league, or confederacy; -- often followed by to or with.
O chief! in blood, and now in arms allied. --Pope.
2. To connect or form a relation between by similitude, resemblance, friendship, or love.
These three did love each other dearly well,
And with so firm affection were allied. --Spenser.
The virtue nearest to our vice allied. --Pope.
Note: ☞ Ally is generally used in the passive form or reflexively.