catch at (something)(redirected from catch them at)
catch at (something)
1. To find or see someone in the act of doing something (often something nefarious). In this usage, the guilty party is stated between "catch" and "at." The detective was able to catch the robbers at their next scheme.
2. To grasp at or clutch something. She must be nervous—she keeps catching at her purse.
catch someone at somethingand catch someone doing something
to discover someone doing something, especially something bad or shameful. We caught her at her evil deeds. Don't let me catch you doing that again!
Snatch, grasp, as in The beggars kept catching at their coats. [c. 1600] Also see grasp at straws.