brachygraphy
A system of writing using abbreviations or special characters; shorthand.
countable, obsolete, uncountable
I would for these causes wish him that is melancholy […] to impose some task upon himself, to divert his melancholy thoughts: to study the art of memory […] , or practise brachygraphy, etc., that will ask a great deal of attention […]
Where it comes from
From French brachygraphie, from Ancient Greek βραχύς (brakhús, “short”) + -γραφία (-graphía, “writing”).
Adapted from the Wiktionary entry brachygraphy (CC BY-SA 4.0).