What is the latin word for ultimate?

It actually depends on how you use it. If you are saying, for example, "this is the best gift", then you would use , "optimum". Use the translation, "optimum", when speaking about an object. When speaking about a masculine Word, such as "father", "brother", "man", then you would use the translation, "optimus". When using a feminine Word such as, "mother", "sister", or "woman", then use the translation, "optima". So it would be, "optima mater", which is translated as "best mother"

I hope this helped!