The phrase "defensive lapses" refers to mistakes or failures that happen when trying to defend or protect something, usually in a sports context. Full definition
Groh was fired this week, but while Foster certainly won't be, the Hokies have begun to suffer some serious defensive lapses of their own in 2012. (sbnation.com)
Maybe Asamoah makes up for these lapses by always being concentrated during game - time whereas, Alex Sandro becomes complacent at times with some, once in a while, defensive lapses which can be costly against big sides. (sbnation.com)
But as has so often been the case, Perth's defensive lapses let them down. (espnfc.com.ar)