A void space of the breadth of a line, on a printed page; a blank line.(adjective)
Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)
Use "white line" in a sentence
"TheHalicarnassus zoomed through the dawn, arriving at the northern coast of Libya, soaring over the frothy white line where the waters of the Mediterranean meet the shores of the North African desert."
"Blisters formed on his scalp, and his lips were pressed together in a tight white line of pain—but he stared at me, stared as if none of it mattered—just me and him, me and him, like the old days."
"The purpling waters drew a sharp white line of foam at the base of the shore; against its irregular eminences, hotels and villas flashed from the greyish verdure of olive and eucalyptus; and the background of bare and finely-pencilled mountains quivered in a pale intensity of light."