Moon
A four letter word that starts with J and ends with M: jism.
A four-letter word for "jug" starting with "e" is usually "ewer."
mend
Item.
MeatMateMakeMindMineMintMoodMeekMaleMailMassmast
mess
mademailmalemikemildmenumilk
manx
m-i-t-t.
Mock.
A mild oath that starts with "e" is usually "egad." Perhaps the "m" is incorrect.
Modernize is a word that starts with m and means to upgrade.