Running together in space, as parallel lines; going on side by side, as proceedings; occurring together, as events or circumstances; existing or…

attributive or adj. Of a door: Double. Of lines: Parallel. Cf. gemel, n. 1b.

Situated or placed side by side (with one another); running side by side, parallel.

Of lines (esp. straight ones), planes, surfaces, or concrete things: lying or extending alongside each other and always at the same distance apart…

Always preserving the same distance (from another line, etc.); parallel.

Existing or moving side by side; esp. (of winds) coming from the same half of the compass. Now rare.

Mathematics. = non-concurrent, adj. 1. Now rare.