a cap·pel·la 
(ä′ kə-pĕlə)
(ä′ kə-pĕlə)adv.
Music
Music
Without instrumental accompaniment.
[Italian : a, in the manner of + cappella, chapel, choir.]
- spectre
- spectrin
- spectro-
- spectrogram
- spectrograph
- spectrographic
- spectrographically
- spectrography
- spectroheliogram
- spectroheliograph
- spectroheliographic
- spectroheliography
- spectrohelioscope
- spectrohelioscopic
- spectrometer
- spectrometric
- spectrometry
- spectrophotometer
- spectrophotometric
- spectrophotometry
- spectroscope
- spectroscopic
- spectroscopical
- spectroscopically
- spectroscopic analysis