The english language leaves us a few clues to follow.

First clue,

Marrubium (horehound) is a genus of about 40 species of flowering plants in the family Lamiaceae, native to temperate regions of Europe and Asia.

The genus name Marrubium derives from the Hebrew marrob or bitter juice. The common name horehound is of unknown origin, but with the first part 'hore' derived from "hoary", "hairy".

http://en.wikipedia.org/wiki/Marrubium

There are different explanations of the name horehound. One explanation is that it is from an Old English word for a grayish plant, horhune, and was influenced by the word hound. Another explanation is that the name horehound may derive from its having been an ancient antidote for the bite of a rabid dog, hore coming from hoar, meaning "old" or "grey."

http://www.wisegeek.com/what-is-horehound.htm

The Romans esteemed Horehound for its medicinal properties, and its Latin name of Marrubium is said to be derived from Maria urbs, an ancient town of Italy. Other authors derive its name from the Hebrew marrob (a bitter juice), and state that it was one of the bitter herbs which the Jews were ordered to take for the Feast of Passover.

The Egyptian Priests called this plant the 'Seed of Horus,' or the 'Bull's Blood,' and the 'Eye of the Star.' It was a principal ingredient in the negro Caesar's antidote for vegetable poisons.

http://www.botanical.com/botanical/mgmh/h/horwhi33.html

More Clues?

hoar 

O.E. har "gray, venerable, old," the connecting notion being gray hair, from P.Gmc. *khairaz, from PIE *koi- "to shine." Ger. retains the word as a title of respect, in Herr. Of frost, it is recorded in O.E. (hoar-frost is c.1290), expressing the resemblance of the white feathers of frost to an old man's beard. Used as an attribute of boundary stones in O.E. (probably in ref. to being gray with lichens), hence common in place names.

Online Etymology Dictionary, © 2001 Douglas Harper
 

hoary ..HOR-ee.., adjective:
1. White or gray with age; as, "hoary hairs."
2. Ancient; extremely old; remote in time past.

Hoary derives from Middle English hor, from Old English har, "gray; old (and gray-haired)."

hor
mountain. (1.) One of the mountains of the chain of Seir or Edom, on the confines of Idumea (Num. 20:22-29; 33:37). It was one of the stations of the Israelites in the wilderness (33:37), which they reached in the circuitous route they were obliged to take because the Edomites refused them a passage through their territory. It was during the encampment here that Aaron died (Num. 33:37-41). (See Aaron.) The Israelites passed this mountain several times in their wanderings. It bears the modern name of Jebel Harun, and is the highest and most conspicious of the whole range. It stands about midway between the Dead Sea and the Elanitic gulf. It has two summits, in the hallow between which it is supposed that Aaron died. Others, however, suppose that this mountain is the modern Jebel Madurah, on the opposite, i.e., the western, side of the Arabah.

(2.) One of the marks of the northern boundary of Palestine (Num. 34:7, 8). Nowhere else mentioned. Perhaps it is one of the peaks of Lebanon.

hor

Hor, who conceives, or shows; a hill

Easton's 1897 Bible Dictionary

http://dictionary.reference.com/ 

Another Clue?

Hore Abbey 

'Hore' is thought to derive from 'iubhair' – yew tree. The former Benedictine abbey at Hore was given to the Cistercians by Archbishop David MacCearbhaill (in 1270), who later entered the monastery. He endowed the Abbey generously with land, mills and other benefices previously belonging to the town. The story, beloved of tour-guides, that he evicted the Benedictines after a dream that they were about to kill him, is unlikely to be true and probably arises from the Archbishop's 'interference' with the commerce of the city of Cashel. His disfavour of the established orders in Cashel certainly caused local resentment. He was resented by some of the towns-people, being considered too much in favour of the Irish by the more Anglicised. This is evident in the objection by the thirty-eight local brewers to the levy of two flagons out of every brewing and in the murder of two monks who were visiting the town.

http://en.wikipedia.org/wiki/Hore_Abbey 

our roots?

The HORE Family Crest

Where did the English Hore family come from? What is the English coat of arms/family crest? When did the Hore family first arrive in the United States? Where did the various branches of the family go?  What is the history of the family name?

The first dictionaries that appeared in the last few hundred years did much to standardize the English language. Before that time, spelling variations in names were a common occurrence. The language was changing, incorporating pieces of other languages, and the spelling of names changed with it. Hore has been spelled many different ways, including Hoar, Hoare, Hore and others. First found in Suffolk and Middlesex where they were seated from very ancient times, some say well before the Norman Conquest and the arrival of Duke William at Hastings in 1066 A.D.

Thousands of English families in this era began to emigrate the New World in search of land and freedom from religious and political persecution. Although the passage was expensive and the ships were dark, crowded, and unsafe, those who made the voyage safely were rewarded with opportunities unavailable to them in their homeland. Research into passenger and immigration lists has revealed some of the very first Hores to arrive in North America: Thomas Hoar settled in the Barbados in 1685; John Hoar settled in Salem in 1823; Edward Hoare settled in the Barbados in 1685; John Hoare settled in New England in 1630.

http://www.houseofnames.com

to be continued..