The term 'not digital' can be summarized by two crossword solutions: ANALOGUE (8 letters) and ANALOG (6 letters). ANALOGUE and ANALOG refer to a type of signal or device that is not digital. ANALOGUE signals are continuous, meaning they have an infinite number of values between any two points, while digital signals are discrete, meaning they have a finite number of values between any two points. ANALOGUE devices are those that use ANALOGUE signals, such as tape recorders, vinyl records, and old-style television sets. ANALOG devices are those that use ANALOG signals, such as thermometers, voltmeters, and some types of clocks.