converse

Etymology 1

From Old French converser, from Latin conversor (“live, have dealings with”).

verb

1. (formal, intransitive) To talk; to engage in conversation.
2. (followed by with) To keep company; to hold intimate intercourse; to commune.
3. (obsolete) To have knowledge of (a thing), from long intercourse or study.

noun

1. (now literary) Free verbal interchange of thoughts or views; conversation; chat.
   Twice ere the sun descends, with zeal inspir'd, / From the vain converse of the world retir'd, / She reads the psalms and chapters for the day […] 1728, Edward Young, Love of Fame, the Universal Passion, Satire V, On Women, lines 44-46
   In a first-class carriage of a train speeding Balkanward across the flat, green Hungarian plain, two Britons sat in friendly, fitful converse. 1919, Saki, ‘The Disappearance of Crispina Umerleigh’, The Toys of Peace, Penguin 2000 (Complete Short Stories), p. 405

Etymology 2

From Latin conversus (“turned around”), past participle of converto (“turn about”).

adj

1. Opposite; reversed in order or relation; reciprocal.
   a converse proposition

noun

1. The opposite or reverse.
2. (logic) Of a proposition or theorem of the form: given that "If A is true, then B is true", then "If B is true, then A is true.".
   All trees are plants, but the converse, that all plants are trees, is not true.
3. (semantics) One of a pair of terms that name or describe a relationship from opposite perspectives; converse antonym; relational antonym.