Definition of geophone in US English:

geophone

noun

  • A device or instrument used to detect vibrations in the ground, especially sound waves or shock waves.

Origin

Early 20th century; earliest use found in Cosmopolitan. From geo- + -phone, probably after French géophone (although this is apparently first attested slightly later: 1917 or earlier).

Pronunciation

geophone

/ˈdʒiːə(ʊ)fəʊn/