>>However per wikipedia "from the French fuselé "spindle-shaped""
>>it would be perfectly apt.

So, the essence of spindle is that its an oblong rotating object.

You seem to only focus on one word at a time we are talking fuselage frame and spindle shaped.

The definition for fuselage says "spindle-shaped." Nothing about "shaped" requires rotation. If this were the case then "fuselage" being used for aircraft would also be inappropriate.

And we make kayaks with a fuselage frame, so while may not be making a aircraft fuselage, we are using a frame that is like a frame in an airplane's fuselage.

Why do I bother with this whole business? Because there is no need to invent a new world where one sufficient enought already exists.

The world of technical language is full of specific terms for specific things. This is how we differentiate a pebble from a boulder. They are both just rocks, the only difference is size, but it is useful to have terms other than big rock and little rock.

While some people dismiss technical terms a jargon, it is useful for a sailor to be able to differentiate between a rope, a line and a sheet. A sheet is a line made of rope for adjusting a sail, a line is rope that has been put to a specific use, a rope is long skinny flexible stuff awaiting a good use. If a sailor says to release the sheet, you know which line to release so you don't end up lowering the halyard or separating a stay. The jargon saves time by being specific.

In SOF kayaks there are two basic rib types: bent ribs and sawn ribs. In the class of sawn ribs there are several ways to do it. You can use solid wood with curved grain like a guideboat (below).

You can also cut ribs or frames out of plywood, and then cut holes in it to reduce the weight.

It is useful for kayak builders to differentiate between bent and sawn ribs, and sawn ribs has some ambiguity. The term "fuselage" quickly conveys a very exact meaning. It also draws a direct analogy to construction methods outside of boat building that many people are familiar with (maybe through building balsa airplane models as a kid).

So while the French origin of the word is useful, we are speaking English. In English "fuselage" has a meaning as does "frame" and while I have not built a fuselage frame kayak, the first time I heard the phrase I knew exactly what the person was talking about. As the goal of any language is to communicate meaning efficiently, I would say "fuselage frame" is a extremely successful term. I bet that even if you don't like it, the first time you heard the term you understood what they were referring to.

This is English language, craftsmen's forum, the craft we pursue is boatbuilding, the boats we make are kayaks, some people here make strip built, others stitch and glue, and some make skin on frame, of those SOF builders some make their kayaks use methods based on the qajaqs or iqiax of the Inuit or Aleuts respectively. A group of the English speaking, boatbuilding craftsmen here make kayaks using a method similar to building airplanes which they call "Fuselage Frame". May they live long and prosper. 🖖