HyperDic: bob_under

English > 1 sense of the expression *bob under*:
VERB	perception	bob under	disappear suddenly, as if under the surface of a body of water

English > *bob under*: 1 sense > verb 1, perception
Meaning	disappear suddenly, as if under the surface of a body of water.
Pattern	Something ----s; Somebody ----s
Broader	vanish, disappear, go away	Become invisible or unnoticeable / unnoticeable