1) Calm 1) Collected 2) Composed 3) Having or showing equanimity 4) Poised 5) Self-collected 6) Self-contained 7) Self-possessed 
• (a.) Of an even, composed frame of mind; of a steady temper; not easily elated or depressed.
E·quan'i·mous adjective [ Latin aequanimus , from aequus equal + animus mind.] Of an even, composed frame of mind; of a steady temper; not easily elated or depressed. Bp. Gauden. 
equanimous, equanimously, equanimousness 1. Of an even, composed frame of mind. 2. Of a steady temper. 3. Not easily elated or depressed.equanimity, equanimous 1. Mental or emotional stability or composure; especially, under tension or strain; calmness; equilibrium. 2. Being calm and in control of the emotions; especially, in a difficult situation.
having or showing equanimity; even-tempered: It was difficult to remain equanimous in the face of such impertinence.