lagan vs wreckage

lagan and wreckage both are nouns.

Word	Noun	Adjective	Verb	Adverb
lagan	Yes	No	No	No
wreckage	Yes	No	No	No

As nouns, wreckage is a hypernym of lagan; that is, wreckage is a word with a broader meaning than lagan:

lagan: goods (or wreckage) on the sea bed that is attached to a buoy so that it can be recovered
wreckage: the remaining parts of something that has been wrecked

lagan (noun)	wreckage (noun)
goods (or wreckage) on the sea bed that is attached to a buoy so that it can be recovered	the remaining parts of something that has been wrecked