I think it always means 1, at least when I use it and have heard
others.

By the way, a single model can have widely differing sensitivity
depending on cockpit load/CofG position. A well-known 2- seater with a
permissibly light solo pilot (think 16-year old girl on 1st solo) can
be 4x more sensitive than with 2 up, one being an overweight
instructor. She finds herself flying a glider totally different in
feel to anything she has flown before. Can lead to PIO.

No heavy instructor knows what she is going to experience.

So I am told.

Chris N.