Joint the Spanish have to bend (5)
I believe the answer is:
elbow
'joint' is the definition.
(joint of the body)
'the spanish have to bend' is the wordplay.
'the spanish' becomes 'el' ('the' in Spanish).
'have' means one lot of letters go next to another.
'to bend' becomes 'bow' (bowing is a kind of bending).
'el'+'bow'='ELBOW'
(Other definitions for elbow that I've seen before include "Major arm joint" , "Nudging joint?" , "Hinged joint" , "Barge" , "Sharp bend in a road or river" .)