[28] What, on that occasion, is the energy faculty (viriyindriya)?
That which on that occasion is the mental arousal of energy (viriyārambha), striving (nikkama), endeavor (parakkama), exertion (uyyāma), effort (vāyāma), enthusiasm (ussāha), perseverance (ussoḷhī), vigor (thāma), steadfastness (dhiti), the state of unfaltering endeavor (asithila-parakkamatā), the state of not relinquishing zeal (anikkhitta-chandatā), the state of not laying down the task (anikkhitta-dhuratā), the firm upholding of the task (dhura-sampaggāha), energy (viriya), the energy faculty, the power of energy (viriyabala), right effort (sammāvāyāma) — this, on that occasion, is the energy faculty.
English translation from the Pali (Siam Raṭṭha edition) — under review, not for citation.