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.
1 A relative; a kinsman. [Obs.] Shak.
2 One united to another by treaty or league; — usually applied to sovereigns or states; a confederate. The English soldiers and their French allies. Macaulay.
3 Anything associated with another as a helper; an auxiliary. Science, instead of being the enemy of religion, becomes its ally. Buckle.
4 Anything akin to another by structure, etc.
See Alley, a marble or taw.