The term 'small opening' can be described by a variety of words, all of which are crossword solutions. EYELET is a small hole or perforation in fabric or leather, usually reinforced with a metal or plastic ring, and is six letters long. PORE is a tiny opening in the skin, four letters long. SLIT is a narrow cut or opening, also four letters long. Micro is an extremely small object, five letters long. GAP is an empty space between two objects, three letters long. ESS is a three letter word meaning 'small opening'. SLOT is a thin, elongated opening, four letters long. MINI is a very small object, four letters long. Finally, STOMA is an opening in an organ, such as the mouth, five letters long. All of these words describe a small opening in some way, shape, or form.