elongation
noun
[ iːlɒŋˈɡeɪʃ(ə)n ]
• the action or process of lengthening something.
• "the bird's tails become forked through elongation of their outer feathers"
• the angular separation of a planet from the sun or of a satellite from a planet, as seen by an observer.
• "Mercury reaches greatest elongation on the 1st, when it will be 27 degrees west of the Sun"
Origin:
late Middle English: from late Latin elongatio(n- ), from elongare ‘place at a distance’ (see elongate).
