The King in bed is right laugh (6)

I believe the answer is:
scream
'right laugh' is the definition.
'scream' can be an answer for 'laugh' (I've seen this before). I am unsure of the 'right' bit.
'the king in bed' is the wordplay.
'the king' becomes 'CR' (short for Carolus Rex, King Charles in Latin).
'in' means one lot of letters goes inside another.
'bed' becomes 'seam' (synonyms).
'cr' inserted into 'seam' is 'SCREAM'.
'is' is the link.
Can you help me to learn more?
(Other definitions for scream that I've seen before include "Yell in fear" , "Call for" , "Make high shrill sound as from fear" , "Cry of anguish" , "Loud piercing cry" .)
