principium /prin-sipˈi-əm or pring-kipˈi-ŭm/

1. A beginning
2. A first principle or element
3. The general's quarters in a Roman camp

principˈial adjective

Elementary

• double-headed
• double-header
• double-headers
• double-hearted
• double helix
• double-hung
• double indemnities
• double indemnity
• double jeopardy
• double-jointed
• double knit
• double-knit
• double knitting
• double-lived
• double-locked
• double-log
• double-logarithmic
• double majority
• double-manned
• double-meaning
• double-minded
• double-mindedness
• double-mouthed
• double-natured
• double negation