Sycophants beginning to sneak into nation (3,3)
I believe the answer is:
yes men
'sycophants' is the definition.
(I've seen this before)
'beginning to sneak into nation' is the wordplay.
'beginning to' suggests taking the first letters.
'into' indicates putting letters inside.
'nation' becomes 'yemen' (Yemen is an example).
The initial letter of 'sneak' is 's'.
's' put inside 'yemen' is 'YES-MEN'.
(Other definitions for yes men that I've seen before include "They always agree with a superior" , "crawlers?" , "They always agree with bosses" , "Toadies" , "Poodles" .)