Assertion: crack | /r/HasProperty | narrow opening
Facets:
Source sentences:
text: 2. crack - a narrow opening; "he opened the window a crack" gap lacuna, blank - a blank gap or missing part opening - a vacant or unobstructed space that is man-made; "they left a small opening for the cat at the bottom of the door" spark gap - the gap between two high-potential terminals
text: Epoxy injection method is used for cracks as narrow as 0.002 inch (0.05 mm).