1. (noun) a radioactive element of the actinide series; found in uranium ores

• actinium
• atomic number 89

2. (noun) an electric current that reverses direction sinusoidally

• alternating current
• alternating electric current

1. (noun) a radioactive element of the actinide series; found in uranium ores

• chemical element
• element

2. (noun) an electric current that reverses direction sinusoidally

• electrical energy
• electricity

1. (noun) an electric current that reverses direction sinusoidally

• dc
• direct current
• direct electric current