WordNet sense 1 (apprehending and responding with speed and sensitivity):

ready

WordNet sense 2 (having the capacity for thought and reason especially to a high degree):

intelligent

WordNet sense 3 (hurried and brief):

flying

WordNet sense 4 (moving rapidly or performed quickly or in great haste):

hurried

WordNet sense 5 (accomplished rapidly and without delay):

speedy

WordNet sense 6 (performed with little or no delay):

immediate, prompt, straightaway

WordNet sense 7 (acting or moving or capable of acting or moving quickly):

fast

WordNet sense 8 (easily aroused or excited):

warm

WordNet sense 9 (with little or no delay):

promptly, quickly

WordNet sense 10 (moving quickly and lightly):

agile, nimble, spry

WordNet sense 11 (characterized by energetic activity):

active