Stick with a present containing diamonds (6)
I believe the answer is:
adhere
'stick' is the definition.
('adhere' can be a synonym of 'stick')
'a present containing diamonds' is the wordplay.
'present' becomes 'here' ('here' can be similar in meaning to 'present').
'containing' is an insertion indicator.
'diamonds' becomes 'd' (abbreviation in bridge say).
'a'+'here'='ahere'
'ahere' going around 'd' is 'ADHERE'.
'with' is the link.
(Other definitions for adhere that I've seen before include "'Stick to, a play say (6)'" , "Stick with header" , "secure" , "Bond" , "Remain attached" .)