Avoiding multiple `or` expressions

You might prefer something like this:

select *
from foobar
where (subject,term) in ( ('STAT','111')
                         ,('STAT','222')
                         ,('ENGLISH','555')
                         ,('COMM','444')
                         ,('COMM','333')
                         ,('STAT','222')
                         ,('STAT','666') 
                        );

DBFiddle here

In terms of a pure code cleansing, the following looks cleaner:

SELECT * 
  FROM foobar 
  WHERE (SUBJECT = 'STAT' and TERM IN ('111','222','666') )
    OR  (SUBJECT = 'COMM' and TERM IN ('333','444') )
    OR  (SUBJECT = 'ENGLISH' and TERM = '555' ) ;

Depending on the application and how often the logic will be reused, it may also be worth setting up a lookup table to apply the logic:

CREATE TABLE foobar_lookup (SUBJECT VARCHAR2(7), TERM VARCHAR2(3)) ;

INSERT INTO foobar_lookup SELECT 'STAT',    '111' FROM dual ;
INSERT INTO foobar_lookup SELECT 'STAT',    '222' FROM dual ;
INSERT INTO foobar_lookup SELECT 'STAT',    '666' FROM dual ;
INSERT INTO foobar_lookup SELECT 'COMM',    '444' FROM dual ;
INSERT INTO foobar_lookup SELECT 'COMM',    '333' FROM dual ;
INSERT INTO foobar_lookup SELECT 'ENGLISH', '555' FROM dual ;

SELECT f.* FROM foobar f
JOIN foobar_lookup fl 
    ON fl.subject = f.subject
    AND fl.term = f.term ;

Here is another way to do it. Using the where (col1,col2) might cause Oracle to not use any indexes, but this looks like a table to the query, so it might work better. You will know once you test the various versions.

  WITH subject_terms 
            (subject,   term) AS
    ( SELECT 'STAT'   , '111' FROM dual UNION ALL
      SELECT 'STAT'   , '222' FROM dual UNION ALL
      SELECT 'ENGLISH', '555' FROM dual UNION ALL
      SELECT 'COMM'   , '444' FROM dual UNION ALL
      SELECT 'COMM'   , '333' FROM dual UNION ALL
      SELECT 'STAT'   , '666' FROM dual )
SELECT * 
  FROM foobar             fb
 INNER JOIN subject_terms st
    ON fb.subject = st.subject
   AND fb.term    = st.term;

DBFiddle Here