Derivation
Derived from 16th Century English, "coil" refers to tumults or troubles. Used idiomatically, the phrase means "the bustle and turmoil of this mortal life." "Coil" has an unusual etymological history. It was coined repeatedly; at one time people used it as a verb to mean "to cull," "to thrash," "to lay in rings or spirals," "to turn," "to mound hay" and "to stir." As a noun it has meant "a selection," "a spiral," "the breech of a gun," "a mound of hay", "a pen for hens", and "noisy disturbance, fuss, ado." It is in this last sense, which became popular in the 16th century, that Shakespeare used the word.
"Mortal coil"—along with "the slings and arrows of outrageous fortune," "to sleep, perchance to dream" and "ay, there’s the rub"—is part of Hamlet’s famous "To be or not to be" speech. "Coil" is no longer used as a synonym for "disturbance."
Read more about this topic: Mortal Coil