slap something on
phrasal verb with slap verb [ T ] uk/slæp/ us/slæp/ -pp-
（随便地）涂上一层，撒上一层;随意涂抹
to put or spread a substance over a surface very quickly or roughly
We want to sell our house, so we've slapped some paint on the outside to make it look better. 我们想卖掉房子，所以就把外面简单地刷了些漆使其看起来漂亮些。