I'm not very confident but here's my guess: VISA - Each of the themers has a synonym for edge then another word: woman, walls, waters & terrier. Those describe VIOLADAVIS26ATony-winning actress in "Fences"[----------], ISHTARGATE62ABabylonian wonder[----------], SARATOGA43ASprings with a namesake town in New York[--------] & AIREDALE46ADog with a wiry coat[--------], respectively. The leading letters spell VISA. How far off am I?