Fetching details from the dictionary...

to be bulky; to be unwieldy; to grow voluminous
冬物の衣類はかさばるので収納に困る。
Winter clothes are bulky so storage is a problem.
引越しの荷物は思ったよりかさばった。
The moving boxes were bulkier than I had expected.
古いテントは重くてかさばっていた。
The old tent was heavy and bulky.