The term THESIS ABBR. can be summarized with three crossword solutions: DISS (4 letters), IBID (4 letters), and OPCIT (5 letters). DISS stands for Doctor of Philosophy in Social Science, which is a doctoral degree awarded by universities in the United States. IBID is an abbreviation for the Latin phrase 'ibidem', which means 'in the same place'. OPCIT is an abbreviation for the Latin phrase 'opus citatum', which means 'the work cited'. All three terms are commonly used in academic writing to refer to previously cited sources.