louse (something) up, to

louse someone or something up

Inf. to ruin something; to mess someone or something up. You really loused me up! You got me in a real mess! Who loused up my scheme?
See also: louse, up

louse up

Spoil, ruin, bungle. For example, The bad weather loused up our plans, or Your change of mind really loused me up. This slangy expression originated in World War I, when infestation with lice was the common lot of soldiers in the trenches; its figurative use dates from the 1930s.
See also: louse, up

louse up

v.
To cause something to fail because of poor handling; botch something: The president loused up the merger, costing the company millions of dollars. Let me tell the story—you always louse it up.
See also: louse, up

louse (something) up, to

To ruin or botch, to blunder. Undoubtedly alluding to the unhappy condition of being “loused up,” that is, infested with lice, this slangy term dates from the first half of the 1900s. At first it was used as a transitive verb, as in John O’Hara’s Appointment in Samarra, “Lousing up your date.” A decade or two later it was also being used intransitively, as in “Don’t trust her with the reservations; she’s sure to louse up.”
See also: louse