Lose water that's heated, and dry out (9)
I believe the answer is:
dehydrate
'lose water' is the definition.
(I've seen this before)
'heated and dry out' is the wordplay.
'and' says to put letters next to each other (I've seen this in other clues).
'out' is an anagram indicator (out can mean wrong or inaccurate).
'heated' after 'dry' is 'dryheated'.
'dryheated' anagrammed gives 'DEHYDRATE'.
'that's' is the link.
(Other definitions for dehydrate that I've seen before include "Remove water from" , "Remove moisture from, make dry" , "Deprive of water" , "Preserve by removing all liquid from" , "Drain" .)