title: !grepl in for loop to remove rows from a dataframe
body: <p>I want to use a for loop to remove any row that contains a text string of values in another vector. I know I can use regex, but this is a process I repeat regularly, so I want to pass a vector of terms into a loop and then a larger function to save time.</p>
  
  <pre><code># Dataframe that always changes
  keyword &lt;- c('acme regulator','regulator','brand regulator')
  position &lt;- c(1, 23, 3)
  
  # Terms I want to remove that always change
  rmterms &lt;- c('acme','brand')
  
  t_allkwsum &lt;- data.frame(keyword, position)
  
  df &lt;- for (i in 1:length(rmterms)){
       x &lt;- t_allkwsum[!grepl(rmterms[i],t_allkwsum$keyword),]
       df2 &lt;- rbind(df2,x)
       }
  </code></pre>
  
  <p>df returns as NULL. I want it to return any row where an 'rmterms' value isn't present in t_allkwsum$keyword.</p>