Dictionary.net

in full control of your faculties; "the witness remained collected throughout the cross-examination"; "perfectly poised and sure of himself"; "more self-contained and more dependable than many of the early frontiersmen"; "strong and self-possessed in the face of trouble"

Of an even, composed frame of mind; of a steady temper; not easily elated or depressed.

Of an even, composed frame of mind; of a steady temper; not easily elated or depressed.

Even, not dejected.