leger vs cost ledger

leger and cost ledger both are nouns.

Word	Noun	Adjective	Verb	Adverb
leger	Yes	No	No	No
cost ledger	Yes	No	No	No

As nouns, cost ledger is a hyponym of leger; that is, cost ledger is a word with a more specific, narrower meaning than leger:

leger: a record in which commercial accounts are recorded
cost ledger: ledger showing the accumulated costs classified in various ways

Other hyponyms of leger include general ledger, subsidiary ledger, daybook, journal.

leger (noun)	cost ledger (noun)
a record in which commercial accounts are recorded	ledger showing the accumulated costs classified in various ways