To print out the last word in the string:
SQL> declare
2 v1_tx VARCHAR2(20):='Hello to everybody';
3 v2_tx VARCHAR2(20);
4 begin
5 v2_tx:= substr (v1_tx, instr (v1_tx,' ',-1)+1);
6 DBMS_OUTPUT.put_line(v2_tx);
7 end;
8 /
everybody
PL/SQL procedure successfully completed.
SQL>