Bait transported in kilogram container (6)
I believe the answer is:
'container' is the definition.
(kitbag is a kind of container)
'bait transported in kilogram' is the wordplay.
'transported' indicates an anagram.
'in' means one lot of letters goes inside another.
'kilogram' becomes 'kg' (synonyms).
'bait' is an anagram of 'itba'.
'itba' placed within 'kg' is 'KITBAG'.
(Other definitions for kitbag that I've seen before include "knapsack" , "Cylindrical canvas holder for soldiers' clothes" , "Serviceman's canvas pack" .)