ОБОЛОЧКА _|_ SHELL, COAT / OBOLOCHKA [ɐbɐˈɫot͡ɕkə] 

Hint with an alternative definition: it covers an object, imagine a chock-full block with a double coat, a lock & latch to check the safety

Hints with translation + consonant words (by sounds or letters): like a bubble-jacket / awe-blotch = a terrible cover with a bad content

Mental visualization: ОБ (creation of soap bubbles = air shells) + OL (creation of a shell from a sphere) + ОЛ (placental membrane in the abdomen of the mother with the umbilical cord)