'fully-limbed' originates from English, a compound of 'fully' and 'limbed'. 'fully' originates from Old English, specifically the word 'full', where 'full' meant 'filled (to capacity)' or 'complete'; 'limbed' derives from Old English 'lim', where 'lim' meant 'arm' or 'leg'.

'fully' developed from Old English 'full' to Middle English forms like 'ful'/'fulli' (with the adverbial suffix -i), becoming modern 'fully'; 'limb' comes from Old English 'lim' and passed through Middle English forms to become modern 'limb', with 'limbed' formed as an adjectival/past-participle form.

Initially the components meant 'completely' (fully) and 'a limb' (limb); combined as a compound they have retained a straightforward meaning, now expressed as 'having all limbs'.