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.
SYNONYMY NOTE: laugh is the general word for the sounds or exhalation made in expressing mirth, amusement, etc.; , chuckle implies soft laughter in low tones, expressive of mild amusement or inward satisfaction; , giggle, titter both refer to a half-suppressed laugh consisting of a series of rapid, high-pitched sounds, suggesting embarrassment, ...