'aclinic line' definitions:

Definition of 'aclinic line'

(from WordNet)
noun
An imaginary line paralleling the equator where a magnetic needle has no dip [syn: aclinic line, magnetic equator]

Definition of 'aclinic line'

From: GCIDE
  • magnetic equator \magnetic equator\ n. An imaginary line paralleling the equator where a magnetic needle has no dip, the dipping needle being horizontal; called also aclinic line. [WordNet 1.5]