Some state emissaries are exceedingly numerous (4)
I believe the answer is:
teem
'exceedingly numerous' is the definition.
'teem' can be an answer for 'numerous' (I've seen this before). I am not certain of the 'exceedingly' bit.
'some state emissaries are' is the wordplay.
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'TEEM' is hidden in the letters of 'state emissaries are'.
Can you help me to learn more?
(Other definitions for teem that I've seen before include "Pullulate" , "Be swarming (with)" , "Come down hard" , "pelt" , "Be prolific" .)