All 4 Uses

perceptible
in
Moby Dick
(Auto-generated)

And, by and by, it came to pass, that he was almost continually in the air; but, as yet, for all that he said, or perceptibly did, on the at last sunny deck, he seemed as unnecessary there as another mast.†
Chpt 28-30

perceptibly = in a manner that is capable of being noticed
But that thing of his dissembling was only subject to his perceptibility, not to his will determinate.†
Chpt 40-42 *

perceptibility = capability of being noticed
No perceptible face or front did it have; no conceivable token of either sensation or instinct; but undulated there on the billows, an unearthly, formless, chance-like apparition of life.†
Chpt 58-60

perceptible = capable of being noticed
The peeled white body of the beheaded whale flashes like a marble sepulchre; though changed in hue, it has not perceptibly lost anything in bulk.†
Chpt 67-69

perceptibly = in a manner that is capable of being noticed

Definitions:

(1) (perceptible)
capable of being noticed -- typically because it is different enough or large enough
(2) (meaning too rare to warrant focus)