
1) Three-wheeled motor vehicle
Found on
https://www.crosswordclues.com/clue/securus

Latin, meaning: safe, secure, free from care, unworried, unconcerned.
Found on
http://archives.nd.edu/sss.htm

The Securus was a German automobile manufactured only in 1906. A two-speed tricar, it was built in Berlin by Max Ortmann. David Burgess Wise, The New Illustrated Encyclopedia of Automobiles. ...
Found on
http://en.wikipedia.org/wiki/Securus

safe, secure, free from care, unworried, unconcerned.
Found on
https://www.math.ubc.ca/~cass/frivs/latin/latin-dict-full.html
No exact match found.