dowdy - (of a person or their clothes) unfashionable and without style in appearance (typically used of a woman)
When Helen reached the age of 100, she didn't care that people thought that she dressed in a dowdy manner, she contented herself thinking about the wonderful family she had raised.
simmer - To heat a liquid, usually a stew or soup, just below the boiling point, allowing it to cook slowly; or to stay in a slow, controlled state of progress or tension, often before a larger event or change occurs.

He was simmering with anger, but he kept it inside and didn't say out loud what he was thinking and feeling.