The story
Abbreviation of doubled stem, due to the fact that verbs in this stem typically have a doubled second radical.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: the intensive stem/verbal construction of a root, typically denoting intensity, transitivity, and multiplication, particularly in Semitic languages Full definition →
Abbreviation of doubled stem, due to the fact that verbs in this stem typically have a doubled second radical.
Etymology from Wiktionary, CC BY-SA 4.0.