僅（わず）か is a な-Adjective in Japanese that is often used adverbially at the beginning of sentences in order to indicate an excessively small amount of something. 僅（わず）か itself may be translated as ‘trifling’, or ‘meager’, with the adverbial variant being interpreted as ‘merely’, ‘barely’, or ‘slightly’.
As an adverb, 僅（わず）か will appear as 僅（わず）かに.

• この建物（たてもの）は真下（ました）からみると、わずかに傾（かたむ）いているように見（み）える。
  This building appears to tilt slightly when viewed from directly below.
• 隣（となり）の人（ひと）のテレビの音（おと）がわずかに聞（き）こえる。
  I can slightly hear the sound of my neighbor’s TV.
• 建物（たてもの）と建物（たてもの）の間（あいだ）から富士山（ふじさん）がわずかに見（み）えた。
  Mt. Fuji was slightly visible between the buildings.

Due to 僅（わず）か highlighting an extremely small amount of something, it is often used when the speaker is trying to be modest in indicating that something is nothing more than a trifling amount, such as the difference between their and another’s opinions.

• 始（はじ）めた頃（ころ）に比（くら）べると、僅（わず）かに上手（じょうず）になった感（かん）じがします。
  Compared to when I started, I feel I am only slightly better.