In general contexts, something that ossifies becomes hardened or conventional and opposed to change. In medical contexts, something that ossifies (such as cartilage) forms or is transformed into bone.

// I asked if she'd reconsider her position, but her opinions on the matter have clearly ossified.

A propensity is a strong natural tendency to do something.

// As a child, she had a strong propensity for mischief.

Copious is a synonym of abundant and plentiful. It is always used before a noun to describe something very large in amount or number.

// The pie was served with a copious amount of ice cream.

// Jacqueline took copious notes during the long lecture and shared them with the rest of her study group.

A gadabout is a person who flits about in social activity, as by going to many places and social events for pleasure.

// She was a gadabout who was rarely home, and her tiny apartment was cluttered with playbills and other souvenirs of her adventures.

Sentient is a formal term that typically describes beings conscious of or responsive to the sensations of seeing, hearing, feeling, tasting, or smelling.

// An avid gardener, Dorothy has recently been absorbed in books that examine the question of whether, and to what degree, plants are sentient.

Durable describes people or things that last, or remain strong and in good condition over a long period of time. It is often used figuratively, as in "a durable athlete."

// The fabric was durable enough to withstand chewing from the family dog.

// She is one of Hollywood's most durable stars.