wellhead

noun

1. The place where a spring breaks out of the ground; the source of water for a stream or well.

   “Leaue the troubled streames, And liue as Thriuers doe at the Well head.”

   “It is a singular circumstance, that within a quarter of a mile of the well-head of the Wye, arises the Severn.”

   “We set forth accordingly by this itinerary; and for the best part of three nights travelled on eerie mountains and among the well-heads of wild rivers; [...]”

2. (figuratively)The source of something; a fountainhead.

   “[H]e likened was to a welhed / Of euill words, and wicked ſclaunders by him ſhed.”

   “[...] a bull was not merely a stud animal worth so much, due to go to the butcher in a little while. It was a vast wonder-beast, a well-head of the great, furnace-like passion that makes the worlds roll and the sun surge up [...]”

3. The surface structure of an oil well etc.