The word 'ex-citable' refers to someone or something that is easily aroused or stimulated. Antonyms for this word are 'calm', 'collected', 'composed', 'unexcitable' and 'stoic.' If someone is described as 'calm,' it means they remain peaceful and relaxed in difficult situations. 'Collected' describes someone who keeps their emotions in check. 'Composed' means to be self-controlled and poised, while 'unexcitable' refers to someone who cannot be easily stirred up. Finally, 'stoic' describes someone who is indifferent to pleasure or pain. These antonyms all represent an antithesis to the hyper-reflexive nature of 'ex-citable.