The adjective equable means "not easily irritated" or "steady," like someone's equable manner that makes everyone instantly feel comfortable.
To correctly pronounce equable, accent the first syllable: "EK-wah-bul." It comes from the Latin word aequabilis, meaning "equal, consistent, uniform." An equable person isn't moody. You wouldn't expect him or her to fly into a rage one minute and be humming a happy tune the next. Instead, someone who is equable takes things in stride — the good, the bad, and the ugly, with a smile and the occasional reminder that "this too shall pass."