The series of bodily changes that occur in the female of most mammals from one period of estrus to another. The estrous cycle usually takes place during a specific period known as the breeding season, which ensures that the young are born at a time when the chance of survival is greatest.
ear-to-ear. It's about smiling. Ear-to-ear smile or grin is when you have a very broad and generous smile. Such a smile when each corner of your mouth is by each of your ears. Explain to me why you don't have an ear-to-ear grin right now.
verb (used without object), grinned, grinning. 1. to smile broadly, especially as an indication of pleasure, amusement, or the like. 2. to draw back the lips so as to show the teeth, as a snarling dog or a person in pain. 3. to show or be exposed through an opening, crevice, etc. verb (used with object), grinned, grinning.