Possibly a variant of Sayre, meaning a woodworker or sawyer.
Syer is a rare surname-turned-first-name with roots likely tied to the occupational name Sayre. It historically refers to a person who worked with a saw or lived near a marshy area. In modern usage, it is often chosen for its sleek, phonetic appeal and its similarity to names like Sawyer or Cyrus.
Less common today
Syer isn't in the latest US Top 1000. It last peaked at #5,101 in 2021.
US births per 5-year period, 1990βpresent (SSA data).