One entry found for
imperceptible.
Main Entry:
im·per·cep·ti·ble 
Pronunciation:
im-p
r-
sep-t
-b
l
Function:
adjective
1 : not noticeable
: not perceptible by a sense or by the mind <one whose beauty was
imperceptible to others>
2 : hardly noticeable
: very small or gradual <an
imperceptible smile>
-
im·per·cep·ti·bly 
/
-bl
/
adverb