Determined to get relative in while camping (9)
I believe the answer is:
insistent
'determined' is the definition.
(insistent can mean determined or tenacious)
'relative in while camping' is the wordplay.
'relative' becomes 'sis' (short for sister).
'in' indicates putting letters inside.
'while camping' becomes 'intent' (I can't justify this - if you can you should believe this answer much more).
'sis' going within 'intent' is 'INSISTENT'.
'to get' is the link.
Can you help me to learn more?
(Other definitions for insistent that I've seen before include "Unwilling to take "no" for an answer" , "Refusing to be thwarted" , "Constant" , "Unrelenting" , "Compelling attention" .)