1. running in opposite directions while remaining parallel
Usage: geometry; physics
2. having corresponding parts arranged in opposite orientations
Usage: biology; chemistry

Examples

• The two DNA strands run in antiparallel directions.
• The magnetic field lines were antiparallel to each other.
• In the double helix, the sugar-phosphate backbones are antiparallel.
• The vectors point in antiparallel directions along the same line.
• The protein chains showed an antiparallel arrangement.
• Antiparallel beta sheets are common in protein structures.