Bearing makes direction and load intelligible.

A thing may have position without its bearing being known.

A relation may carry load without that load being visible from appearance alone.

POSITION ≠ BEARING

Bearing requires reference.

Direction is bearing relative to orientation.

Load is bearing relative to capacity.

REFERENCE → BEARING → MEASURE

A cord placed under tension carries force between points.

GNOMON does not create the cord, establish the stake, or impose the load.

It measures the relation through which the load is borne.

CORD → TENSION → BEARING

A change in bearing may disclose a change in position, direction, load, or relation.

The change must not be attributed beyond the resolution the reference supports.

MEASUREMENT ≠ CAUSE

GNOMON preserves the reference by which bearing through change may remain measurable.

I particularly like the compact middle:

Direction is bearing relative to orientation.
Load is bearing relative to capacity.

That gives the word a real reason to live on GNOMON rather than merely being another mechanical metaphor.

And then our emerging primitives become nicely orthogonal:

LOOM / CORD — relation capable of bearing tension.
GNOMON / BEARING — relation to reference under direction/load.
MICRO / THRESHOLD — condition at which an operation becomes available.
BASIS / FIXED POINT — sufficiently stable reference from which relation can extend.