Translucent means 'see-through' - as in EB-0 trans-cherry red. Opaque means 'solid' - not able to see through.
Here's an example of a brown MM guitar I mentioned - a '79 Sabre bass. Leo started G&L in '79, but that colour was done during his years with MM. It's hard to tell from this pic whether it is a dark translucent stain or if it is a solid colour. The bigger pic of the MM Stingray I guitar from '78 (from one of my reference books) looks to be a dark walnut stain. The guitar finish looks closer to your brown in hue.
View attachment 3836819 View attachment 3836837
Lol, I should've known this about opaque, but wasn't thinking straight. Derp