The antonyms for the word 'are delirious' can be calm, collected, sane, clear-headed, levelheaded, and composed. Delirium is characterized by uncontrolled excitement or emotions, confusion, disorientation, and hallucinations, so the antonyms are words that describe a state of mind opposite to these states. If someone is calm, they are peaceful and tranquil, and if they are composed, they are relaxed and poised. Being clear-headed and levelheaded means having a stable and rational mind that can think lucidly and make rational decisions. Sanity is another antonym, meaning being mentally stable and free from madness, delusions, or irrational behavior.