unperfected

It's an unperfected invention as yet; we might want to put some more stuff in there for our own private use.

An experiment with an unperfected machine, in the presence of the writer, seemed to justify their hopes.

The wonderful is only the half-developed, unperfected miracle.

Mr. Macauley's literary attainments are very considerable, but as yet unperfected.

In Australia is prevalent a horrible disease due to an "unperfected tapeworm."