circular saw       
noun [ C ] uk/ˌsɜː.kjə.lə ˈsɔː/ us/ˌsɝː.kjə.lɚ ˈsɑː/
 圆锯
an electric saw (= a tool for cutting hard materials) that has a circular blade, sometimes with sharp points along the edge
  Trim the posts to height with a circular saw. 用圆锯把木桩锯到合适的高度。 
 He could hear the sound of hammering, then the whine of a circular saw.  他能听到锤子敲打的声音,然后是圆锯的呜呜声。 
 - More examples
 - Crosscut the 5/4 material into 24-inch lengths for the legs using a circular saw.
 - The screech of a circular saw cut through the silence.
 - The best tool for trimming floorboards is a circular saw.
 - A section of old garden hose can be used to protect the cutting blade on tools such as hoes, scythes and circular saws.
 - Anything over 90 decibels (about the sound created by a circular saw) can cause hearing damage.