"going along with, adjoining," by 1782, present-participle adjective from accompany (v.).
Entries linking to accompanying
accompany v.
early 15c., "to be in company with," from Old French acompaignier "take as a companion" (12c., Modern French accompagner), from à "to" (see ad-) + compaignier, from compaign (see companion). The musical meaning "play or sing along with" is by 1570s. Related: Accompanied; accompanying.