The word "枯燥无味" is formed by combining two two-character phrases: "枯燥", from 枯 (withered) and 燥 (arid), meaning dry and dull, and "无味", from 无 (without) and 味 (flavor), meaning tasteless; together they create a literal sense of "dry and flavorless" to convey figurative meaning of monotony or lack of interest.