BEAT/BEAD |
In American English when you focus narrowly on something or define it carefully you “get a bead” or “draw a bead” on it. In this expression the term “bead” comes from the former name for the little metal bump on the end of a gun barrel which helped the shooter aim precisely at a target. “Beat” is often mistakenly substituted for “bead” by people who imagine that the expression has something to do with matching the timing of the person or activity being observed, catching up with it.