Synonyms and related words :
acuity, acuteness, alacrity, alertness, attention, attentiveness, brightness, briskness, dispatch, expedition, expeditiousness, featliness, keenness, lightness, nimbleness, promptitude, promptness, punctuality, quickness, readiness, sharpness, sleeplessness, smartness, speediness, spryness, swiftness, wakefulness