gui·tar (g?-tär?)n. A musical instrument having a flat-backed rounded body that narrows in the middle, a long fretted neck, and usually six strings, played by strumming or plucking.[French guitare, from Spanish guitarra, from Greek kithar?, cithara.]gui·tar?ist n.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.guitar (???t??) n (Instruments) music a plucked stringed instrument originating in Spain, usually having six strings, a flat sounding board with a circular sound hole in the centre, a flat back, and a fretted fingerboard. Range: more than three octaves upwards from E on the first leger line below the bass staff. See also electric guitar, bass guitar, Hawaiian guitar[C17: from Spanish guitarra, from Arabic q?t?r, from Greek kithara cithara] gui?tarist n gui?tar-?like adjCollins English Dictionary ? Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014gui?tar (g??t?r) n. a stringed musical instrument with a long fretted neck, a violinlike body, and typically six strings plucked with the fingers or with a plectrum. [1615?25;