Prime number: not the first, like two (4)
I believe the answer is:
even
'like two' is the definition.
'even' can be an answer for 'like' (thesaurus). I'm not certain of the 'two' bit.
'prime number not the first' is the wordplay.
'prime number' becomes 'seven' (I've seen this in another clue).
'not the first' means to remove the first letter.
'seven' with its initial letter taken away is 'EVEN'.
Can you help me to learn more?
(Other definitions for even that I've seen before include "Like 2018 but not 2017" , "Level, equal" , "Not easily annoyed" , "Crisp and ---, how King Wenceslas found the snow" , "Like half the numbers" .)