Frenetic means wildly fast and disordered. Everything happening at once and none of it under control.
It describes activity, pace and energy, so a frenetic week and frenetic activity are both standard, and both carry a hint of exhaustion. It is stronger than busy and less organised than hectic, though the two are close. The word comes from the same root as frantic and frenzy, all going back to a Greek word for a disorder of the mind. The adverb is frenetically.
1adjectivefreneticFast, energetic and disordered.
“The last hour before opening was frenetic.”
Frenetic and frantic are the same word. Both come through Latin from Greek phrenitis, delirium, from phrēn, the mind, so frenetic activity was once a diagnosis.
Ancient Greek
φρενητικός — delirious
Latin
phreneticus
Old French
frenetike
Middle English
frenetik
English, today
frenetic
Built from
From Middle English frenetik (also frentik, frentyk, frantike > modern frantic), from Old French frenetike, from Latin phreneticus, from Ancient Greek φρενητικός (“delirious”), from φρενῖτις (“delirium”), from φρήν (“mind”). a doublet of frantic and phrenitic. Etymologically, initial stress would be expected (compare the phrentic); the modern pronunciation with stress on the second syllable is due to the influence of other words ending in -etic such as phonetic and sympathetic.
Etymology from Wiktionary, CC BY-SA