One of the pieces in the current ABRSM Grade 7 violin pieces is Moritz Moszkowski's Spanischer Tanz No. 2 from his Spanische Tänze Op. 12. At the start of bar 49 is the marking "gajo".
According to the interwebs this is Spanish for a segment of citrus fruit. The bar it is on is the start of the middle section of the piece, where we move from G minor to G major. How do I play this like a segment of citrus fruit? What does this directive mean?
In this context, the word "gajo" means joyful or merry. The composer seems to want you to underline the shift to G Major by playing in a noticeably more exuberant style. In most styles of tonal music, the shift from minor to major already implies a change of mood along those lines, but "merry" is a nicely evocative description of the precise shade of "happier" that the shift brings.
To add to the excellent answer by @PatMuchmore, "gajo" has nothing to do with fruit, it is but a slightly antiquated spelling for the Italian "gaio", which means "gay" (which is incidentaly a cognate word), whose interpretative meaning is self-explaining: play gayly :)
