No, it's all right, this is easy. You've been using hendiadys more or less all your life: hendiadys is just the clever name for it.
Hendiadys basically comes about when, instead of using one word for a thing and another word to describe it, as in:
the dinner was sitting in a pool of greasy gravy
you join the two words together with an and, tweak one of them a bit, and say:
the dinner was sitting in a pool of grease and gravy.
That's more or less all there is to it, really.
Jolly powerful and effective it can be, too.
Do not, as some ungracious pastors do,
Show me the steep and thorny way to heaven
Whiles, like a puffed and reckless libertine,
Himself the primrose path of dalliance treads
And recks not his own rede.
Nuts and Bolts: hendiadys. This word is a Latinised form of the Greek phrase hen dia duoin, which means one through two.