Tissue a body needs, crying about private upset (8)
I believe the answer is:
ligament
'tissue a body' is the definition.
'ligament' can be an answer for 'tissue' (I've seen this before). I am not sure about the 'a body' bit.
'crying about private upset' is the wordplay.
'crying' becomes 'lament' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'about' means one lot of letters goes inside another.
'private' becomes 'GI' (GI can informally mean a US soldier).
'upset' says the letters should be written in reverse.
'gi' back-to-front is 'ig'.
'lament' going around 'ig' is 'LIGAMENT'.
'needs' acts as a link.
Can you help me to learn more?
(Other definitions for ligament that I've seen before include "Tough, bone-linking tissue" , "Joint connector" , "Tissue which joins bones" , "Link between bones or cartilages" , "sheet of tissue" .)