what does RSZDT mean ?

in

PROCESS STATE CODES -different values that the s, stat and state output specifiers(header "STAT" or "S") will display to describe the state of a process.

D Uninterruptible sleep (usually IO)
R Running or runnable (on run queue)
S Interruptible sleep (waiting for an event to complete)
T Stopped, either by a job control signal or because it is being traced.
W paging (not valid since kernel 2.6.xx)
X dead (should never be seen)
Z Defunct ("zombie") process, terminated but not reaped by its parent.