c. 1300, recoveren, "to regain consciousness," also "regain health or strength after sickness, injury, etc.," from Anglo-French rekeverer (13c.), Old French recovrer "come back, return; regain health; procure, get again" (11c.), from Medieval Latin recuperare "to recover" (source of Spanish recobrar, Italian ricoverare; see recuperation).
The sense of "get (anything) back, get or regain possession or control of," literally or figuratively, after it has been lost, is attested from mid-14c. In law, "obtain by judgment or legal proceedings," late 14c. The transitive sense of "restore from sickness, restore (another) to health" is from c. 1600; that of "rescue, save from danger" is from 1610s. Related: Recovered; recovering. To recover arms (1680s) is to bring the piece from the position of "aim" to that of "ready."
Australian evergreen tree, commercially important for its edible nut, 1904, from Modern Latin (1858), named for Scotland-born chemist Dr. John Macadam, secretary of the Victoria Philosophical Institute, Australia, + abstract noun ending -ia.
"healthfulness, state or character of being healthful," early 15c., salubrite, Old French salubrite and directly from Latin salubritas, from salubris "promoting health, healthful" (see salubrious).
by 1839 as "hospital, usually private, for the treatment of invalids, convalescents, etc., who might benefit from open air;" by 1842 as "place to which people go for the sake of health or to regain health;" Modern Latin, noun use of neuter of Late Latin adjective sanitorius "health-giving," from Latin sanat-, past-participle stem of sanare "to heal," from sanus "well, healthy, sane" (see sane).
Latin sanare is the source of Italian sanare, Spanish sanar. Century Dictionary  notes it was "specifically applied to military stations on the mountains or tablelands of tropical countries, with climates suited to the health of Europeans."
Many of his patients had asked him what this hard word sanatorium meant, and he explained to them, that it was a lodging-house, which was, in fact, the proper alias of sanatorium, and that it was to the benefit of Dr. Arnott's stove and of regularity in the time of giving medicine. [from report on a "Debate on the Sanatorium" in The Lancet, Jan. 11, 1840]
"to grow better after sickness, make progress toward the recovery of health," late 15c., from Latin convalescere "thrive, regain health, begin to grow strong or well," from assimilated form of com-, here perhaps an intensive prefix (see com-), + valescere "to begin to grow strong," inchoative of valere "to be strong" (from PIE root *wal- "to be strong"). Only in Caxton and Scottish writers until 19c. Related: Convalesced; convalescing.
late 14c., saluten, "to greet courteously and respectfully," earlier salue (c. 1300, from Old French salver), from Latin salutare "to greet, pay respects," literally "wish health to," from salus (genitive salutis) "greeting, good health," which is related to salvus "safe" (from PIE root *sol- "whole, well-kept").
The military and nautical sense of "display flags, fire cannons, etc., as a mark of ceremonious recognition or respect" is recorded from 1580s; specific sense of "raise the hand to the cap in the presence of a superior officer" is from 1844. In 18c. use often "to greet with a kiss."