From Longman Dictionary of Contemporary Englishthrow in/cast your lot with somebody/somethingthrow in/cast your lot with somebody/somethingto join or support someone or something, and accept that what happens to them will affect what happens to you In 1915 Italy threw in her lot with the Allies. → lot
Examples from the Corpus
throw in/cast your lot with somebody/something• At the next meeting of the Unionist Cabinet Ministers Boscawen threw in his lot with me.• Desperate to win in the third most conservative state, Bush threw in his lot with the religious right.• The Dance caught on everywhere, and eventually Sitting Bull himself threw in his lot with the shakers.• All you have to do is throw in your lot with me.• Like Dudley Williams, Jamison threw in her lot with Alvin early on, at the start of her career.• She threw in her lot with the Jowles.• I suppose we are right to throw in our lot with them. 