am·bi·ent 
(ămbē-ənt)
(ămbē-ənt)adj.
1. Surrounding; encircling: ambient sound; ambient air.
2. Relating to or being instrumental or electronic music that has melody, gentle rhythm, and limited harmonic development and is intended to induce a relaxed mood.
[Latin ambiēns, ambient-, present participle of ambīre, to surround : amb-, ambi-, around; see AMBI- + īre, to go; see ei- in the Appendix of Indo-European roots.]