crown jewels defence
noun[S]
UK(UScrown jewels defense)ukusanactionthat acompanytakestoavoidbeingboughtby anothercompany, in which itsellsitsmostvaluableassets, so that it is nolongersoattractiveto the secondcompany:
Theyattemptedtowardofftakeoverbymountingacrownjewelsdefence.