Second cross held in palm maybe about to protrude (6)
I believe the answer is:
exsert
'to protrude' is the definition.
(I've seen this before)
'second cross held in' is the wordplay.
'second' becomes 'esert' (I can't justify this - if you can you should believe this answer much more).
'cross' becomes 'x' (an X is a cross).
'held in' means one lot of letters goes inside another.
'esert' going around 'x' is 'EXSERT'.
'palm maybe about' acts as a link.
This may not be correct. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for exsert that I've seen before include "Protrude; exerts (anag.)" , "stick out" , "Put out" .)