|Origin:||alier, from Latin alligare, from ad- 'to' + ligare 'to tie'|
al‧ly2 past tense and past participle allied, present participle allying, third person singular allies
[transitive always +adverb/preposition]
to help and support other people or countries, especially in a war or disagreement
ally yourself to/with somebody
Some of the northern cities allied themselves with the emperor.