Starts to get under table - such courage! (4)
I believe the answer is:
guts
'courage' is the definition.
(I've seen this before)
'starts to get under table such' is the wordplay.
'starts to' suggests taking the first letters.
The initial letters of 'get under table such' is 'GUTS'.
(Other definitions for guts that I've seen before include "Fortitude - innards" , "Intestinal courage?" , "Courage; entrails" , "stamina!" , "Courage, determination" .)