Bitcoin library - how to check number of confirmations
"confirmed" in this case means the transaction is included in at least one block that belongs to the current best chain. 

If you want to find out exactly how many confirmations each transaction has you can use fetch-history to get a full list of all transactions sent to and from your address. fetch-history will return the block number that the transaction has been included in. You can then use that along with the current height to figure out how many confirmations your transaction has. 

bx fetch-history 1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa
bx fetch-height