- spectro-
- spectrogram
- spectrograph
- spectroheliogram
- spectroheliograph
- spectrohelioscope
- spectrometer
- spectrophotometer
- spectroscope
- spectroscopic analysis
- spectroscopic binary
- spectroscopies
- spectroscopy
- spectrum
- spectrums
- specula
- specula
- specular
- speculate
- speculated
- speculates
- speculating
- speculation
- speculations
- speculative