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).
Definition of geophone in US English:
geophone
nounˈdʒiːə(ʊ)fəʊn
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).