jactation

jac•ta•tion (jak-tey-shuhn)   n

Definition
1. (pathology) a tossing or shaking of the body; physical agitation, especially while asleep or confined to bed by illness
2. the action of throwing
3. boasting; bragging; showing off

jactitation
 1. (law) a false boast or claim that is intended to harm someone, especially a malicious claim by a person that he or she is married to a particular person
2. involuntary tossing and twitching of the body and limbs

jaculation
hurling or throwing

Related
Related Words: ejaculation

Examples
• There are crises of convulsions, violent shouting, loud weeping, violent jactation, fainting, and semi-coma.
• Thus a sentence of jactitation of marriage only imports, that it did not appear that the parties were married at a particular time and place, and not that there was no marriage at any time or place.
• 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. Bleak House, Dickens

The Storyline
But Kurt was roused from his stupor and Anna wheeled about at the sounds of Tyler's sudden jactations.

Origin
jactation
1570–80; Latin jactatare , "to throw." equiv. to jacta-t ( us ) (ptp. of jacta-re,  freq. of jacere  to throw) + -io-n-  -ion

jactitation
1625–35; from Latin jactitation (tossing, false declaration), past participle of jactitare (to throw out publicly, to boast), frequentative of jactare (to throw about), frequentative of jacere (to throw)

jaculation
1615–25;  < L jacula-tus  (ptp. of jacula-re  to throw the javelin), equiv. to jacul ( um ) javelin (n. use of neut. of jaculus  used for hurling, equiv. to jac-  hurl + -ulus  adj. suffix) + -a-tus -ate

Sources: Wicktionary, Wordsmith, Dictionary.com

Why This Word:
Three similar words. Two disparate meanings. What gives? My handy Latin-English Dictionary helps. (Doesn't everyone have one?)
jactantor: boastfully
jactatio: tossing to and fro
jactator: braggart
jacto: to throw, cast
Of course, what would be really helpful would be if I could find some source to sort this out. But it sure seems like two very similar Latin words became conflated and two out of our three English words today acquired both meanings.
The surviving sense of jactation is toss about, with a rarer use of boasting. The surviving sense jactitation is a boast, albeit of a specialized nature, with a rarer use of tossing about. And the surviving form of jaculation, is, well, that word - you know.
In any event, this mash up of meaning and words gives us a bit of a glimpse into the messiness of language change. We think of etymologies as clear chains of lineage. But apparently not always.

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