antiparallel
noun
Definitions
A line that forms equal angles with two other lines, but in opposite directions.
adjective
Definitions
Of vectors, parallel but of opposite direction
Describing the orientations of the two strands of DNA
Describing two beta strands comprising a protein's secondary structure that are aligned and hydrogen bonded but the vector describing the amino- and carboxy-terminal ends of each strand are oriented 180° relative to one another.