Ad libitum

Ad libitum is Latin for "freely". In music, this instruction means to play with free time; that is, ignore strict note values and dynamics. This allows for more expressive music, and is a form of improvisation.

---

Ad libitum is also used in psychology and biology to refer to the "free-feeding" weight of an animal, as opposed, for example, to the weight after a restricted diet. C.f., The rat's ad libitum weight was about 320 grams.

Free-fed animals are often less healthy than animals with restricted diets--as is true of humans, as well. Excess weight is highly correlated with a variety of health threatening disorders.