Castile soap also cas·tile soap 
(kăs-tēl)
(kăs-tēl)n.
A soap made with vegetable oil, especially olive oil, and sodium hydroxide.
[After Castile.]
- second home
- secondi
- second lieutenant
- second line
- second-line
- secondly
- second mortgage
- second nature
- secondo
- second of arc
- Secondo Tranquillo.
- second person
- second-person
- second quantum number
- second-rate
- second-rateness
- second-rater
- second sight
- second-story man
- second-strike
- second string
- second-string
- second-stringer
- second thought
- second wind