Dictionary

1. (

• niobium ,
• Nb ,
• atomic_number_ ,

) a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium ;

2. (

• nota_bene ,
• NB ,
• N.B.

) a Latin phrase (or its abbreviation) used to indicate that special attention should be paid to something; "the margins of his book were generously supplied with pencilled NBs" ;