1. The estimated or near-final stage of finishing a project, task, or process, without being completely finished
The construction project is nearing approximate completion.
O projeto de construção está chegando perto da conclusão aproximada.
2. A target date or timeframe expected for the finish of work, with some allowance for variation
We expect approximate completion by the end of next quarter.
Esperamos a conclusão aproximada até o final do próximo trimestre.