Jaculation is the act of throwing or hurling something. Hardly a common word at any time, this is as dead as can be, now only to be found fossilised within the pages of the very largest dictionaries. It appeared about 1610, at almost exactly the same date as its close relative ejaculation. Both are from the Latin verb iaculari, to hurl.
Charles Dickens employed this rare word in Bleak House:
Grandfather Smallweed immediately throws the cushion at her. “Drat you, be quiet!” says the good old man. The effect of this act of jaculation is twofold. It not only doubles up Mrs. Smallweed’s head against the side of her porter’s chair and causes her to present, when extricated by her granddaughter, a highly unbecoming state of cap, but the necessary exertion recoils on Mr. Smallweed himself, whom it throws back into HIS porter’s chair like a broken puppet.
Almost the only place you will find it, or at least the agent noun jaculator for one who hurls, is in the formal name for the archer fish of Asia, Toxotes jaculator, which catches insects by squirting a jet of water at them. There’s also a parasitic wasp called Gasteruption jaculator, which deposits her eggs into the larvae of bees, though it is less obvious what this insect throws, if anything. But one may with justice argue that neither word is English, but scientific Latin.