Like some puzzles in mathematics (8)
I believe the answer is:
thematic
'like some puzzles' is the definition.
(some crossword puzzles are thematic)
'in mathematics' is the wordplay.
'in' says the answer is hidden in the clue.
'THEMATIC' is hidden in the letters of 'mathematics'.
(Other definitions for thematic that I've seen before include "Related to a particular subject" , "Relating to a particular subject" , "Relating to a motif" , "on one particular topic" , "With a unifying subject" .)