In electronics, two anti-parallel or inverse-parallel devices are connected in parallel but with their polarities reversed.
One example is the TRIAC, which is comparable to two thyristors connected back-to-back (in other words, reverse parallel), but on a single piece of silicon.
Two LEDs can be paired this way, so that each protects the other from reverse voltage. A series string of such pairs can be connected to AC or DC power, with an appropriate resistor. With AC, the LEDs in each pair take turns emitting light, on alternate half-cycles of supply power. Some two-color LEDs are constructed this way, with the two dies connected anti-parallel in one casing.