The crossword solutions for the term 'Fill with Gas' are FUEL (4 letters) and AERATE (6 letters). FUEL is a noun that refers to any material used to produce energy, such as gasoline, diesel, or coal. AERATE is a verb that means to supply air or oxygen to something, usually to improve its quality. Therefore, the phrase 'Fill with Gas' can be interpreted as adding FUEL to an engine or aerating a liquid or gas to improve its quality.