From Longman Dictionary of Contemporary Englishfieldmousefield‧mouse /ˈfiːldmaʊs/ noun (plural fieldmice /-maɪs/) [countable] HBAa mouse that has a long tail and lives in fields
Examples from the Corpus
fieldmouse• All he saw as he glanced at her was his little wife, shy as a fieldmouse, clinging to his hand.• He came back in the evening, bringing Lyn a fieldmouse. 