1
general::
Not in working order, unable to function. For example, The drawbridge is out of commission so we'll have to take the tunnel. This idiom originally referred to a ship that was laid up for repairs or held in reserve. Similarly, the antonym, in commission, referred to a ship armed and ready for action. The latter term is Also used in more general contexts today, as in My car's back in commission now, so we can drive to the theater. [Late 1800s]
American Heritage Idioms
2
general::
Phrase(s): out of commission
1. Lit. [for a ship] to be not currently in use or under command. • This vessel will remain out of commission for another month. • The ship has been out of commission since repairs began. 2. Fig. broken, unserviceable, or inoperable; not currently in use. • My watch is out of commission and needs a new battery. • I can’t run in the marathon because my knees are out of commission.
McGrawhill's American Idioms And Phrasal Verbs