The term 'PERTAIN TO' can be broken down into three crossword solutions: CONCERN (7 letters), REFER (5 letters), and BEARUPON (8 letters). CONCERN means to relate to or have an effect on something, while REFER means to direct the attention of someone to a particular thing. BEARUPON is a combination of the words 'BEAR' and 'UPON, ' which together mean to have an influence on or affect something. All three words together describe the meaning of 'PERTAIN TO, ' which is to have relevance or connection to something.