doubly

the word 'doubly' is formed by combining the adjective 'double', which traces back to the latin 'duplus' (from 'duo' meaning 'two' and '-plus' meaning '-fold'), with the prolific old english adverbial suffix '-ly'. this suffix, originating from a proto-germanic adjective-forming element meaning 'body, form, like', evolved into a standard way to create adverbs from adjectives in english. thus, 'doubly' literally means 'in a double manner', directly conveying the sense of twofold degree or dual nature. its logical progression from the concrete notion of 'twofold' to the abstract adverbial function exemplifies a clear and consistent morphological construction in english.

Structure: double (twofold) + ly (adverb-forming suffix) 'double' originates from old french 'doble', from latin 'duplus' meaning 'twofold, double'. 'ly' is an old english adverbial suffix derived from proto-germanic -līko.