Answer:

bleb

Answer	Crossword Clue
BLEB	Bubble found in glass.
BLEB	Water bubble.
BLEB	Air bubble, in water or glass.

BLEB	Blister.
BLEB	Small blister
BLEB	Air bubble
BLEB	Glass bubble
BLEB	Blister
BLEB	Bubble or blister
BLEB	Bubble

Crossword

a puzzle consisting of a grid of squares and blanks into which words crossing vertically and horizontally are written according to clues.