Actually, both words are French, with ogive (oh-jive) meaning "pointed arch." Meplat (mee-plah) refers to a flat, which describes the frontal portion of a bullet, with the dimension usually given in calibers.
There's a tremendous portion of the ballistic lexicon that is French in origin, since they are (or have traditionally been) some of the most innovative developers of in the field of firearms and ballistics. The term "Spitzer" is German, but even there, the French had developed the pointed bullet first, and merely kept it so secret that the Germans are generally (and incorrectly) given credit for its creation. Even the G series of drag models (G1, G5, G7, etc.) were named as an homage to the Gavre Commission, one of the earliest studies of the drag characteristics of various bullet shapes. Long list of other French terms in this field, if you just stop to think about it a bit.