Spot on, Toalisi, do what the instruction says with your four sets of unclued lights (take a letter from Easter to get the apple, for example - the same with one I know you have - the pain-killer - and so on) then look in the bottom left hand corner of the grid - look up that word in Chambers. OK?
Thanks for the pointer robinruth ... this is the first time I've attempted this puzzle, and had finalised it with the exception of solving the preamble. All clear now.
However, I must thank Kayakamina for explaining the wordplay (by e-mail) on some of the solutions. I had the answers, but couldn't fully justify all of them.
Sarumite - well done for managing this one as a first Speccie - they are not usually nearly so difficult. We've been doing it for years and I would put this as one of the hardest. I don't know whether Kayakamina agrees.