to a first approximation

adj. 1. [techspeak] When one is doing certain numerical computations, an
approximate solution may be computed by any of several heuristic methods,
then refined to a final value. By using the starting point of a first
approximation of the answer, one can write an algorithm that converges more
quickly to the correct result. 2. In jargon, a preface to any comment that
indicates that the comment is only approximately true. The remark To a first
approximation, I feel good might indicate that deeper questioning would
reveal that not all is perfect (e.g., a nagging cough still remains after an
illness).

