The Messenger of Allah ﷺ used to call a female horse a faras.
حدثنا موسى بن مروان الرقي حدثنا مروان بن معاوية عن أبي حيان حدثنا أبو زرعة
أن رسول الله ﷺ كان يسمي الأنثى من الخيل فرسا
[Its chain is hasan] Hakim narrated it (2/144) through the hadith of Musa bin Marwan with this wording. Ibn Hibban graded it sahih (Hadith: 1634), and Hakim said it meets the standard of the two sheikhs, and Dhahabi agreed with him.Marwan bin Muawiya explicitly stated that he heard it directly.