This person, breaking funny bone, petrified mother (5)
I believe the answer is:
niobe
'petrified mother' is the definition.
'niobe' can be an answer for 'petrified' (I've seen this before). I'm unsure of the 'mother' bit.
'this person breaking funny bone' is the wordplay.
'this person' becomes 'I' (the person writing).
'breaking' means one lot of letters goes inside another.
'funny' is an anagram indicator.
'bone' with letters rearranged gives 'nobe'.
'i' inserted within 'nobe' is 'NIOBE'.
Can you help me to learn more?
(Other definitions for niobe that I've seen before include "figure of myth" , "She cried" , "Greek woman cast in stone" , "Mother, her children slaughtered" , "Petrified" .)