The term 'At No Cost' can be expressed in four different ways in a crossword puzzle. The first is 'FREE', which is a four letter word meaning without cost or charge. The second is 'GRATIS', which is a six letter word meaning without payment or charge. The third is 'XTRA', which is a four letter word meaning an extra or additional item given without charge. The fourth is 'FORFREE', which is a seven letter word meaning without cost or charge. All of these words express the same concept, that something is being given without any cost or charge.