SWINGBYS is a playable word

swingby Scrabble® Dictionary

noun
pl. swingbys
a mission in which a spacecraft uses a planet's gravitational pull for making course changes
59 Playable Words can be made from "SWINGBYS"
   2-Letter Words (6 found)
   3-Letter Words (19 found)
   5-Letter Words (8 found)
   6-Letter Words (2 found)
   7-Letter Words (1 found)
   8-Letter Words (1 found)