Jack obtains things that are aimed at (7)
I believe the answer is:
targets
'that are aimed at' is the definition.
I can't tell whether this defines the answer.
'jack obtains' is the wordplay.
'jack' becomes 'tar' (both are informal terms for sailor).
'obtains' becomes 'gets' ('get' can be a synonym of 'obtain').
'tar'+'gets'='TARGETS'
'things' acts as a link.
Can you help me to learn more?
(Other definitions for targets that I've seen before include "Aim points" , "objectives of firing people" , "Reference points to shoot at" , "Goals" , "Butts" .)