adagio [It]—slow tempo, often implying a lyrical, poignant character
Air [Fr], Air [E], Ayre [E], Aire, Aria [I]—Song. Traditionally indicates a piece of melodic or vocal nature as opposed to one of dance-like character (i.e. in form or rhythm). An aria typically refers to a formalized song within an opera context for one or more voice
chamber music, Kammermusik [G], musique de chambre [F], musica da camera [I], musica cameralis [L]—"Classical Music" for a small ensemble, generally 8 or fewer players with a canonical emphasis on 3-6 players. explore
continuo, basso continuo, b.c., figured bass, thorough bass, basse chifrée—During the Baroque Era, a term for an improvised (realized) instrumental accompaniment specified by a symbolic notation for chords and a written bass line (i.e. figured bass). A continuo "part" usually implies multiple (but typically unspecified) instruments, e.g. one for a strong bass line (e.g. cello) and another for chords (e.g. lute, keyboard, organ). A continuo part may be realized by keyboard alone, and sometimes played by a bass melody instrument alone (without harmonies). wiki
presto—very fast, more so than allegro.
sonata, sonate, suonato—a complicated term. Originally, "sounded" rather than "sung" (sonar vs. cantar), e.g. instrumental music. According to historical period, sonata began to imply a formal plan of movements as well as the structure within a single movement, e.g. sonata form. In general usage as a work title, it designates a multi-movement piece for solo or duo instruments with one of the instruments enjoying a feature role.
variation, variazione, variatio, variato, variata—a modified re-iteration of a previous theme, reprise, couplet, etc. The music is varied, embellished or creatively transformed for variety while maintaining a unity relationship with the original. See "Theme and Variations."
violin sonata—a multi-movement work for violin and keyboard (or continuo) though there are sonatas for solo violin as well as sonatas in a single movement. While the violin would seem to be the featured instrument, many sonatas starting with the classical period find the piano to be an equal partner in the sense of a chamber work for two players.