Webster Dictionary (4.00 / 1 vote) Rate this definition: Proficiency (noun) the quality of state of being proficient; advance in the acquisition of any art, science, or knowledge; progression in knowledge; improvement; adeptness; as, to acquire proficiency in music
Additional terms include: 1  retrocessed uterus: both the superior and inferior ends of the uterus are pushed posteriorly.  severely anteflexed uterus: the uterus is in the same position as normal and bends in the same direction (concave is anterior) but the bend is much more pronounced.
1 Endometriosis â the endometrium is the lining of the uterus. Endometriosis is the growth of endometrial cells outside the uterus. These cells can cause retroversion by âgluingâ the uterus to other pelvic structures.  Fibroids â these small, non-cancerous lumps can make the uterus susceptible to tipping backwards.