direct current

American  

noun

1. Electricity. an electric current of constant direction, having a magnitude that does not vary or varies only slightly. dc

---

direct current British  

noun

1.  DC.  a continuous electric current that flows in one direction only, without substantial variation in magnitude Compare alternating current

---

direct current Scientific  

/ dĭ-rĕkt′ /

1. An electric current that moves in one direction with constant strength. Batteries are a source of direct current. Direct current is not used for long-distance power transmission because it is difficult to step up the voltage to a level that is efficient for energy transfer and then to step the voltage back down again for safe domestic use.

2. Compare alternating current See Notes at current Tesla

---

direct current Cultural  

1. The electric current (see also current) in which the electrons flow in one direction only. (Compare alternating current (AC).)

---

Discover More

DC is usually supplied by batteries.

Other Word Forms

• direct-current
  adjective

Etymology

Origin of direct current

First recorded in 1885–90

Compare meaning

How does direct-current compare to similar and commonly confused words? Explore the most common comparisons:

• direct current vs. alternating current

Example Sentences

For efficiency reasons, data centers are transitioning to using more direct current, or DC, electric systems, as opposed to the alternating current that most of the broader electric grid uses.

From Barron's • Apr. 29, 2026

The dawn of the electrical age was constrained by a logistical bottleneck: Thomas Edison’s direct current systems could only transmit power about a mile before the voltage degraded.

From The Wall Street Journal • Apr. 24, 2026

The SUV has a range of 261 miles and can charge from 10% to 80% in as little as 43 minutes with a direct current fast charger.

From Los Angeles Times • Aug. 13, 2025

A new converter station is being built close to Peterhead power station from where high voltage direct current cables will be laid on the seabed.

From BBC • Aug. 13, 2024

And of course Edison urged the fair to use direct current, DC, the prevailing standard.

From "The Devil in the White City" by Erik Larson