noun

• (usually in the plural) A small ball of chemical pesticide (typically naphthalene) and deodorant placed in or around clothing and other articles susceptible to damage from mold or moth larvae in order to protect them from this damage.

verb

• (transitive) To store or shelve something no longer used.
  "They mothballed the old version after the new one came out."
• (transitive, figuratively) To stop using (something), but keep it in good condition.
  "Some schools might have an art studio, an area of forestry in the playground, or a performance stage in the hall – all exceptional assets. Just check they get plenty of use and aren't mothballed while the school concentrates on (you guessed it) maths and literacy."