provisional

1. Temporary or tentative.

2. Something allowed, made, or used until the correct, definitive, or permanent successor is available or comes into being. See also conditional and contingent.

Imagine slaving for years on a new cellphone battery that lasts more than two days, only to watch it reverse-engineered and patented by someone else. Before you ask anyone to crank out a few prototypes, file for a provisional patent. It protects your idea for a year while you work out the kinks.