awk '!/the_string/' file.txt
Assuming a file, test.txt, exists with the following contents:
10 Peter Terence Roux 45 11 Virginia Genevieve Roux 45 12 Felix Devon Roux 5 13 David Bruce Stevenson 48 14 Bob James Smith 16 48 Adam Winter Ridley 23
Running
awk '!/Roux/' test.txt
returns:
13 David Bruce Stevenson 48 14 Bob James Smith 16 48 Adam Winter Ridley 23