sym-sym- /sɪm/ prefix 
the form used for syn- before the letters b, m, or p
the form used for syn- before the letters b, m, or p- freebooter
- freeborn
- Free Church
- Free Church of Scotland
- free collective bargaining
- freedom
- freedom fighter
- Freedom of Information Act
- Freedom Tower
- free enterprise
- free fall
- free-falling
- free-floating
- Freefone
- underwent
- underwhelm
- underworld
- underwrite
- underwriter
- Underwriters' Laboratories
- undeserved
- undesirable
- undetected
- undeterred
- undeveloped