Theodore Roosevelt initially admits regret? That's more like it! (5)
I believe the answer is:
truer
'that's more like it' is the definition.
(I've seen this before)
'theodore roosevelt initially admits regret?' is the wordplay.
'initially' indicates taking the first letters.
'admits' indicates putting letters inside (to admit is to allow in).
'regret?' becomes 'rue' (to rue something is to regret it).
The first letters of 'theodore roosevelt' is 'tr'.
'tr' enclosing 'rue' is 'TRUER'.
(Other definitions for truer that I've seen before include "More real" , "More straight and veracious" , "More in accordance with fact" , "That's more like it" , "More relaible" .)