Definition 1 of 1
To divide one item (typically food) to two roughly equal portions, for sharing. Commonly a sign of both affection and cheapness.
The truly unique aspect of this is that the item is brought already divided, and each gets a little extra bakshish in the bargain. This in fact makes One-by-two a noun in certain contexts.
Boss, can you one-by-two the samosa?
Added 2011-06-28 by Studmuffin