What is "to go it alone"

Go \Go\, v. t.

1. To take, as a share in an enterprise; to undertake or become responsible for; to bear a part in.

   They to go equal shares in the booty.
   --L'Estrange.

2. To bet or wager; as, I'll go you a shilling. [Colloq.]

   To go halves, to share with another equally.

   To go it, to behave in a wild manner; to be uproarious; to carry on; also, to proceed; to make progress. [Colloq.]

   To go it alone (Card Playing), to play a hand without the assistance of one's partner.

   To go one's way, to set forth; to depart.