Word Origin and History for semi-Expand before vowels sem-, word-forming element meaning half, part, partly; partial, imperfect; twice, from Latin semi-half, from PIE *semi-half (cf. Sanskrit sami half, Greek hemi-half, Old English sam-, Gothic sami-half).
Well-known rodents include mice, rats, squirrels, prairie dogs, porcupines, beavers, guinea pigs, hamsters, gerbils and capybaras. Other animals such as rabbits, hares, and pikas, whose incisors also grow continually, were once included with them, but are now considered to be in a separate order, the Lagomorpha.
The Mustelidae family (which also includes badgers, otters, and wolverines) is often referred to as the weasel family. In the UK, the term weasel usually refers to the smallest species Mustela nivalis (the least weasel) but the totally weasel type species but not actually called weasel is the stoat.