Mokosh (Мокошь) is the Slavic earth mother goddess — the only female deity in Prince Vladimir's pre-Christian Kievan pantheon (980 CE). Patroness of women, spinning, weaving, and the fertility of the earth.
Her name survives in many East Slavic toponyms.
Mokosh does not currently appear in the US Social Security Administration's top 1,000 girls' names, so we don't publish a US rank or birth count for it. That says nothing about the name's standing elsewhere in the world — only that it sits outside the ranked US data we rely on.
In Pythagorean numerology the letters of Mokosh reduce to 9, The Giver. This is a traditional interpretive system, not a factual claim about the name.