the word 'tailless' is a transparent modern english compound formed by combining the noun 'tail' with the adjective-forming suffix '-less'. the old english root for 'tail' likely referred specifically to a hairy appendage, a meaning which broadened over time. the suffix '-less' originates from an old english adjective meaning 'free from' or 'void of', itself derived from a concept of being loose or separate. therefore, the literal construction 'tail-less' logically and directly conveys the state of being without a tail, a formation common in english for denoting the absence of a feature.

Structure: tail (rear appendage) + less (without) tail: from old english 'tægl', 'tagl' (tail, hairy appendage), a germanic word of uncertain deeper origin. functions as the base noun. less: from old english '-lēas' (devoid of, free from), from a germanic root meaning 'loose'. functions as a suffix forming adjectives meaning 'without'.