Omissions are words, phrases, or parts of a sentence that are left out intentionally or unintentionally. The three crossword solutions for the term 'omissions' are 'OVERSIGHTS' (10 letters), 'ELLIPSES' (8 letters), and 'elisions' (8 letters). OVERSIGHTS are unintentional omissions, while ELLIPSES and elisions are intentional omissions. ELLIPSES are used to indicate an omission of words, while elisions are used to omit sounds or syllables from a word.