chip away at
Verb
Meaning
remove or withdraw gradually:
Source: WordNetSynonyms
Hypernyms
Examples
Romney still enjoys the Republicans' traditional advantage among voters who are veterans, but the Obama campaign is confident it can chip away at that.
Twitter taught me how to become better at writing jokes because it forces you to chip away at all the extraneous words.
Mining created Chile. The story of men who go down into the mountain and chip away at minerals in the darkness and then suffer an accident that leaves them at the mercy of that darkness is part of the DNA of Chile, an integral part of the country's history.
These new customs are chipping away at the quality of life