This read-only Counter counts frames the CPU dropped while attempting to transmit them, typically because of buffer exhaustion rather than a wire-level problem. A nonzero and growing value here, especially when ciscoTsStackSwitchPendingSendRqsts is also elevated, is a strong signal the switch's CPU transmit path is oversubscribed, for example from too many software-forwarded frames queuing up during a broadcast storm. This is the CPU-level counterpart to ciscoTsPortStatsOutBufOverflows, which tracks the same failure mode at individual ports.