SLUGHORN
Etymology
Noun
slughorn (plural slughorns)
(obsolete) A battle cry. [early 16th C.]
(nonstandard, rare) A wind instrument.
Usage notes
• The sense “a wind instrument” is a construction due to Thomas Chatterton who used the term (incorrectly) in this way in his 1760s pseudo-Medieval poetry. He describes the fictional instrument in footnotes as “warlike instruments of music” (Ælla, a Tragycal Enterlude), “a musical instrument not unlike a hautboy” (Eclogue the Second), and “war trumpets” (Battle of Hastings (No. 2)). The term was then erroneously continued by Robert Browning in 1855. The use by Terry Pratchett in 1989 is a deliberate allusion to Chatterton's construction.
Source: Wiktionary
Slug"-horn`, a.
Definition: An erroneous form of the Scotch word slughorne, or sloggorne,
meaning slogan.
Source: Webster’s Unabridged Dictionary 1913 Edition