the GNU version of the Collaborative International Dictionary of English
n. See mummichog.
The Century Dictionary and Cyclopedia
n. A salt-water minnow, the common killifish. Fuudulus heteroclitus; also, one of numerous other small cyprinodonts, killifishes or top-minnows. See killifish. Also written mummachog, mummichog, mammichug, mammy-chug.