Final answer:
The Italian articulation mark 'accelerando' means to speed up the tempo of the music.
Step-by-step explanation:
The Italian articulation mark 'accelerando' means to speed up the tempo in music. When musicians see 'accelerando' in their music score, they gradually increase the tempo or speed of the music. It is indicated by the abbreviation 'accel.' or by an arrow pointing to the right. For example, if a piece of music is marked 'accelerando', the tempo will gradually get faster as the musician continues to play.