direct current 

https://doi.org/10.1351/goldbook.D01767
This term and its symbol, idc or Idc, should be used (in preference to 'current' alone) only to denote the steady (time-dependent) component of a current that also has a periodic component.
Source:
PAC, 1985, 57, 1491. (Recommended terms, symbols, and definitions for electroanalytical chemistry (Recommendations 1985)) on page 1495 [Terms] [Paper]