basset horn(n = noun.artifact) - a tenor clarinet; pitched in the key of F below the B-flat clarinet;
is a kind of clarinet

   An instrument blown with a reed, and resembling a clarinet, but of much greater compass, embracing nearly four octaves; The corno di bassetto. [1913 Webster]

N  musical instruments, band, string-band, brass-band, orchestra, orchestrina, monochord, polychord, harp, lyre, lute, archlute, mandola, mandolin, mandoline, guitar, zither, cither, cithern, gittern, rebeck, bandurria, bandura, banjo, bina, vina, xanorphica, viol, violin, fiddle, kit, viola, viola d'amore, viola di gamba, tenor, cremona, violoncello, bass, bass viol, base viol, theorbo, double base, contrabasso, violone, psaltery, bow, fiddlestick, piano, pianoforte, harpsichord, clavichord, clarichord, manichord, clavier, spinet, virginals, dulcimer, hurdy-gurdy, vielle, pianino, Eolian harp, organ, harmonium, harmoniphon, American organ, barrel organ, hand organ, accordion, seraphina, concertina, humming top, flute, fife, piccolo, flageolet, clarinet, claronet, basset horn, corno di bassetto, oboe, hautboy, cor Anglais, corno Inglese, bassoon, double bassoon, contrafagotto, serpent, bass clarinet, bagpipes, union pipes, musette, ocarina, Pandean pipes, reed instrument, sirene, pipe, pitch-pipe, sourdet, whistle, catcall, doodlesack, harmoniphone, horn, bugle, cornet, cornet-a-pistons, cornopean, clarion, trumpet, trombone, ophicleide, French horn, saxophone, sax, buglehorn, saxhorn, flugelhorn, althorn, helicanhorn, posthorn, sackbut, euphonium, bombardon tuba, cymbal, bell, gong, tambour, tambourine, tamborine, drum, tom-tom, tabor, tabret, tabourine, taborin, side drum, kettle drum, timpani, tympani, tymbal, timbrel, castanet, bones, musical glasses, musical stones, harmonica, sounding-board, rattle, tam-tam, zambomba, reed, tuning fork, triangle, Jew's harp, musical box, harmonicon, xylophone, sordine, sordet, sourdine, sourdet, mute, (iv) PERCEPTION OF SOUND.

air horn, automobile horn, baritone horn, bass horn, basset, basset hound, basset oboe, bugle horn, cape horn, car horn, english horn, french horn, horn, horn button, horn fly, horn in, horn of africa, horn of plenty, horn poppy, huntsman's horn, little horn, morsing horn, motor horn, post horn, powder horn, ram's horn, saddle horn, spindle horn