Completely stumped on 21d.Put on touch of eyeshadow - that's completed. (5)
15d Latin book, etched for free. (9) 5d Schooner at divided island where loner shows appeal in an irksome way. (10, 10) 18d Fabric from Salerno pedlar in nationwide alert. (7,7).
Thank you in advance
One of the solutions to each pair of clues is one letter less than the number indicated. You have to add a letter then anagram it. The letters are in alphabetical order starting with the across clues then the down clues. The extra letters to add to the across clues go from a to m (in that order) and those for the down clues run from n to z. The clues resulting in a letter short alternate from being the first to the second part of the clue.