"fathom" + "pass"

fathom

American sailors use this word to mean a depth of six "feet" (~1.8 m)

• Middle English fathome ("fathom")
  • Old English fæþm ("outstretched arms")
    • Proto-West Germanic *faþm ("outstretched arms")
      • Proto-Germanic *faþmaz ("outstretched arms")
        • PIE *pet-, *peth2- ("to spread out", "to fly")

pass

"to go from one spot to another"

• Middle English passen ("pass")
  • Old French passer ("step", "walk", "pass")
    • Vulgar Latin *passāre ("step", "walk", "pass")
      • Latin passus ("a step")
        • Proto-Italic *pat-s-tus ("spread out")
          • PIE *peth2- ("to spread out", "to fly")

other words

also stemming from PIE *peth2-:

• French pas ("step")
• English pace ("step")
• Greek πετάνομαι petanomai ("fly")
• Sanskrit पतति patati ("to fly")
• Pali पतति patati ("to fall")