I was thinking about the word plica, which describes a disorder in which women pull, twist, chew, and swallow their hair, sometimes resulting in a hideous hairball known as a bezoar, or, more precisely, a trichobezoar.
...Anyway, I was trying to pull out words that would explain the connection with hair, and I stumbled across a trove, most of which have the suggestion of fold, grow or add in.
Thus, we have folds of two, three, four, two-faced things:
Should you have a plot (a word that is also related), you could add to your fold an accomplice; certain clues might be used to fold in or implicate him; new obstacles that arose might be folded with your original task, as complications. Your only hope might be to unfold, fold out or explicate your motives.
Surely a reply is a fold back and a supply is a fold under. The derivation of application would seem to be fold onto but that's fetching far.
And in case you think the bag of words is running empty, what is one to make of these words?
I hope this will simplify the perplexing task of understanding words!