Sentience

Sister Corvin wrote a thesis entitled "The Echo of Life", concerning the migration of sentience. (TV: New Earth) According to Jingo Linx, the variety of sentient life forms was infinite. (TV: The Time Warrior)

According to Rafando, all sentient beings had an entry in the Fatality Index. (TV: Extremis)

As recalled by Kenossium, the Moment was a weapon so powerful that its operating system became sentient. (TV: The Day of the Doctor)

The Headless Monks paid Dorium Maldovar in sentient money. (TV: Prequel (A Good Man Goes to War))

House was a sentient asteroid. (TV: The Doctor's Wife)

Behind the scenes

 * Though the original philosophical definition of "sentience" focused on the ability to feel, as distinct from the ability to reason, the term is often used in science-fiction and fantasy to refer to beings possessing consciousness akin to a human's, which is the meaning which seems to be reflected by the term's use in Doctor Who fiction.