18-letter words containing o, s, i, f, e, r
- wild passionflower — the maypop, Passiflora incarnata.
- writ of assistance — a writ issued by a superior colonial court authorizing officers of the British crown to summon aid and enter and search any premises.
- yelloweye rockfish — a red rockfish, Sebastes ruberrimus, of waters along the Pacific coast of North America, having eyes that are yellow and possessed of strong, sawlike bony ridges on the head.
- zone of saturation — the ground below the water table