"Gels" refers to gel-like substances, such as hair gel, styling gels, or other toiletries that are in gel form. These substances can often be considered as T.S.A. (Transportation Security Administration) no-nos, as they may be subject to restrictions when carrying them onto airplanes or through airport security.
Note: The provided meaning of the answer is for the latest New York Times crossword puzzle clue: Some T.S.A. no-nos. Explanations are generated by AI and may be inaccurate.