a soft gray ductile metallic element used in alloys; occurs in niobite; formerly called columbium
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"
a Latin phrase (or its abbreviation) used to indicate that special attention should be paid to something
a soft grey ductile metallic element used in alloys; occurs in niobite; formerly called columbium
