M

[monkey]

See:

[GREASE MONKEY],

[MAKE A FOOL OF] or [MAKE A MONKEY OF].

[monkey around]

See:

[FUCK AROUND],

[HORSE AROUND],

[MESS AROUND].

[monkey business]  {n.},  {slang},  {informal}

1. Any unethical, illegitimate, or objectionable activity that is furtive or deceitful, e.g., undercover sexual advances, cheating, misuse of public funds, etc.

* /There is a lot of monkey business going on in  […]

[monkey on one's back]  {n. phr.},  {informal}

An unsolved or nagging problem.

"My math course is a real monkey on my back," Jack complained.

Compare: [ALBATROSS AROUND ONE'S NECK], [MILLSTONE AROUND ONE'S NECK].

[monkey wrench]

See: [THROW A MONKEY WRENCH].

[monster]

See: [GREEN-EYED MONSTER].

[month in, month out]

See: [DAY IN AND DAY OUT].

[month of Sundays]  {n. phr.},  {informal}

A very long time. — Used for emphasis after "for" or "in" and usually with a negative verb.

I have not had devil's food cake in a month of Sundays.

* /When he got her first letter, he felt that he had not  […]

[moon]

See:

[ASK FOR THE MOON] or [CRY FOR THE MOON],

[DARK OF THE MOON],

[FULL OF THE MOON],

[ONCE IN A BLUE MOON],

[PROMISE THE MOON].

[moonshine]  {n.}

Illegally distilled alcoholic beverage made at home, mostly on a farm.