Definition of Mike-Mike in English:
Mike-Mike
(also mike-mike)
noun
US
military slang
Especially in the war in Vietnam: a weapon, or ammunition, the calibre of which is measured in millimetres; a millimetre (chiefly attributive).
Origin
1960s; earliest use found in Esquire Magazine. From Mike + Mike, after mm.
Pronunciation
Mike-Mike
/ˌmʌɪkˈmʌɪk/